Method and system for correcting phase of image reconstruction signal

ABSTRACT

An image generating device for obtaining an image of an object, comprising: a control module configured to generate a first signal having a first frequency component and a first phase component for a first axis direction, and a second signal having a second frequency component and a second phase component for a second axis direction, an emitting unit configured to emit light to the object using the first signal and the second signal; and a light receiving unit configured to obtain light receiving signal based on returned light from the object.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2020-0156041, filed on Nov. 19, 2020 and KoreanPatent Application No. 10-2020-0156042, filed on Nov. 19, 2020, thedisclosure of which is incorporated herein by reference in its entirety.

BACKGROUND 1. Field of the Invention

The present invention relates to a method and system for correcting thephase of an image reconstruction signal, and more particularly, to animage correction method and system that are used to correct the phase ofa reconstruction signal when an image generation device generates animage.

2. Discussion of Related Art

An image generation device is for acquiring an image of an object byemitting light to the object and is widely used in various fields suchas Light Detection and Ranging (LiDAR), optical microscope, endoscope,and endo-microscope.

In particular, since an image generation device may acquire an image ofan object in real time, the image generation device can continuouslyacquire images of the object and thus can also acquire a video of anobject changing in real time as well as still images. However, when animage generation device emits light to an object using a pattern,distortion may occur in an image generated in real time because thepattern of the light is different from the actual position ofinformation on the light acquired by the image generation device.

Accordingly, in order to acquire the accurate position of theinformation on the light that is acquired by the image generation devicein real time, computation for correcting the phase of a signal forenabling the image generation device to reconstruct information on lightreturned from an object may have to be performed.

SUMMARY OF THE INVENTION

The present invention is directed to providing a method ofreconstructing an image using a tendency and a method and system forconstructing the phase of a reconstruction signal for reconstructing animage.

The present invention is also directed to providing a method and systemfor selecting the frequency of an image reconstruction signal in orderto capture a high-resolution image.

The present invention is also directed to providing a method and systemfor transforming the domain of an image reconstruction signal to correctan image.

According to an embodiment of the present invention, there may beprovided a method of correcting the phase of a reconstruction signal inorder to increase the resolution of an image acquired by an imagegeneration device, the method including acquiring an initial phasecorrection value of an initial reconstruction signal, acquiring a firstphase correction value from the initial phase correction value on thebasis of a first slope-based minimum search technique, and acquiring asecond phase correction value on the basis of the first phase correctionvalue when a difference value between pieces of light informationacquired for at least one pixel of an image acquired based on acorrected reconstruction signal is less than or equal to a predetermineddifference value. The image may be acquired based on the reconstructionsignal and the light information, and the second phase correction valuemay be acquired from the first phase correction value on the basis of asecond slope-based minimum search technique, and the first slope-basedminimum search technique may have a different phase search unit from thesecond slope-based minimum search technique.

According to an embodiment of the present invention, an image generatingdevice for obtaining an image of an object, comprising: a control moduleconfigured to generate a first signal having a first frequency componentand a first phase component for a first axis direction, and a secondsignal having a second frequency component and a second phase componentfor a second axis direction, an emitting unit configured to emit lightto the object using the first signal and the second signal; and a lightreceiving unit configured to obtain light receiving signal based onreturned light from the object, wherein the control module configured toobtain a first data set based on the first signal, the second signal andthe light receiving signal, wherein the first signal and the secondsignal correspond to a first domain, wherein the control moduleconfigured to obtain a third signal and a fourth signal, wherein thethird signal and the fourth signal correspond to a second domain,wherein the control module configured to obtain a second data set basedon the third signal and the fourth signal, wherein the first data setand the second data set are different, wherein the control moduleconfigured to obtain an adjusting value of the first data set based onthe second data set, wherein the control module configured to obtain athird data set based on adjusting the first data set using the adjustingvalue, and wherein the control module configured to obtain the image ofthe object base on the third data set.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent to those of ordinary skill in theart by describing exemplary embodiments thereof in detail with referenceto the accompanying drawings, in which:

FIG. 1 is a schematic diagram showing a configuration of an imagegeneration device according to an embodiment;

FIG. 2 includes diagrams showing a pattern in which light is emitted anda pattern which is for image reconstruction according to an embodiment;

FIG. 3 shows a schematic diagram showing a portion of an imagegeneration device including a driver 130 and a fiber 310 according to anembodiment, and shows a cross-sectional view of the driver 130 and thefiber 310 when viewed from the front according to an embodiment;

FIG. 4 is a flowchart illustrating a method of an image generationdevice acquiring data for reconstructing an image according to anembodiment;

FIG. 5 is a table schematically showing light information acquiredaccording to time information according to an embodiment;

FIG. 6 is a table schematically showing light information correspondingto coordinate information according to an embodiment;

FIG. 7 is a schematic diagram showing light information acquired foreach pixel of an image to reconstruct an image according to anembodiment;

FIG. 8 is a flowchart illustrating a method of acquiring one frame sothat an image is acquired according to an embodiment;

FIG. 9 includes diagrams showing that the form of a pattern changesalong with the change in frequency of a signal that generates thepattern according to an embodiment;

FIG. 10 is a flowchart illustrating a method of an image generationdevice acquiring data in which the phase of a reconstruction signal iscorrected according to an embodiment;

FIG. 11 includes diagrams showing an original image of an object and animage of the object reconstructed based on a reconstruction signal witha phase delay according to an embodiment;

FIG. 12 is a table schematically showing coordinate information andlight information corresponding to the coordinate information on thebasis of a reconstruction signal with a phase delay according to anembodiment;

FIG. 13 includes schematic diagrams showing that a mechanical coupling(MC) phenomenon occurs when the fiber 310 is driven according to anembodiment;

FIG. 14 is a flowchart illustrating a method of a controller 110performing phase correction according to an embodiment;

FIG. 15 includes diagrams showing an image acquired according to adomain of a reconstruction signal according to an embodiment;

FIG. 16 includes diagrams showing an image of a phase domain in whichthe phase of a reconstruction signal is not delayed and an image inwhich the phase of a reconstruction signal is delayed by usingcoordinate information acquired in the phase domain according to anembodiment;

FIG. 17 is a flowchart illustrating a method of the controller 110acquiring an initial phase correction value of a reconstruction signalon the basis of symmetry of phase domain coordinate informationaccording to an embodiment;

FIG. 18 is a table schematically showing light information acquired forcoordinate information acquired in the phase domain of a reconstructionsignal according to time information according to an embodiment;

FIG. 19 includes graphs showing that light information for each piece ofcoordinate information is added up based on the coordinate informationacquired in the phase domain according to an embodiment;

FIG. 20 is a flowchart illustrating the order in which an approximatephase correction value of an initial phase correction value is acquiredaccording to an embodiment;

FIG. 21 includes diagrams showing an image acquired when an MCphenomenon has occurred and an image acquired when an MC phenomenon hasnot occurred by using coordinate information acquired in the phasedomain according to an embodiment;

FIG. 22 is a flowchart illustrating a method of the controller 110acquiring a detailed phase correction value according to an embodiment;

FIG. 23 is a schematic diagram showing a plurality of pieces of lightinformation acquired for one piece of pixel information according to anembodiment;

FIG. 24 is a flowchart illustrating a method of the controller 110adjusting the phase of a reconstruction signal and comparing the minimumvalues of light information acquired for pixel information to acquire adetailed phase correction value according to an embodiment;

FIG. 25 is a flowchart illustrating a method of the controller 110additionally adjusting the phase of a reconstruction signal andacquiring a detailed phase correction value according to an embodiment;

FIG. 26 includes diagrams showing that the form of a generated patternis repeated along with a change in the phase of a driving signal or areconstruction signal according to an embodiment;

FIG. 27 is a diagram showing that a fill factor (FF) is repeatedaccording to the phases of a first-axis signal and a second-axis signalof a driving signal or a reconstruction signal according to anembodiment;

FIG. 28 is a diagram showing the density of light information acquiredfor pixel information in the entire pixel range according to anembodiment;

FIG. 29 includes diagrams showing light information or coordinateinformation acquired for pixel information of a partial region of anacquired image according to an embodiment;

FIG. 30 is a flowchart illustrating a method of performing phasecorrection on the basis of light information or coordinate informationacquired in a partial pixel region according to an embodiment;

FIG. 31 includes schematic diagrams showing an intersection of a patternexhibited according to a driving signal or a reconstruction signalaccording to an embodiment;

FIG. 32 is a flowchart illustrating a method of the controller 110correcting the phase of a reconstruction signal by using lightinformation acquired for coordinate information of an intersection of apattern exhibited by a driving signal or a reconstruction signalaccording to an embodiment;

FIG. 33 includes schematic diagrams showing intersections acquired fromdifferent patterns according to an embodiment;

FIG. 34 includes graphs showing a difference value between pieces oflight information acquired for at least one piece of pixel informationexhibited when the phase of a reconstruction signal is changed accordingto an embodiment;

FIG. 35 is a graph showing a difference value between pieces of lightinformation acquired for at least one piece of pixel informationaccording to the phase of a reconstruction signal when the controller110 changes the phase of the reconstruction signal to a phase indicatinga specific FF according to an embodiment;

FIG. 36 is a flowchart illustrating a method of the controller 110acquiring a final phase correction value of a reconstruction signalusing a tendency according to an embodiment;

FIG. 37 is a graph showing a difference value between pieces of lightinformation acquired for at least one piece of pixel informationexhibited when the phase of a reconstruction signal is changed in apartial phase domain of the reconstruction signal according to anembodiment; and

FIG. 38 is a flowchart illustrating a method of the controller 110acquiring a final phase correction value of a reconstruction signalusing a slope-based minimum search technique according to an embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The above objects, features, and advantages of the present inventionwill become more apparent from the following detailed description takenin conjunction with the accompanying drawings. Since the presentinvention may be variously modified and have several exemplaryembodiments, specific embodiments will be shown in the accompanyingdrawings and described in detail.

In the figures, the thickness of layers and regions is exaggerated forclarity. Also, when it is mentioned that an element or layer is “on”another element or layer, the element or layer may be formed directly onthe other element or layer, or a third element or layer may beinterposed therebetween. Like reference numerals refer to like elementsthroughout the specification. Further, like reference numerals will beused to designate like elements within the same scope shown in thedrawings of the embodiments.

Detailed descriptions about well-known functions or configurationsassociated with the present invention will be ruled out in order not tounnecessarily obscure subject matters of the present invention. Itshould also be noted that, although ordinal numbers (such as first andsecond) are used in the following description, they are used only todistinguish similar elements.

The suffixes “module” and “unit” for elements used in the followingdescription are given or used interchangeably only for facilitation ofpreparing this specification, and thus they are not assigned a specificmeaning or function.

The method according to an embodiment may be implemented in the form ofprogram instructions executable by a variety of computer means and maybe recorded on a computer-readable medium. The computer-readable mediummay include program instructions, data files, data structures, and thelike alone or in combination. The program instructions recorded on themedium may be designed and configured specifically for an embodiment ormay be publicly known and available to those skilled in the field ofcomputer software. Examples of the computer-readable recording mediuminclude a magnetic medium, such as a hard disk, a floppy disk, and amagnetic tape, a optical medium, such as a compact disc read-only memory(CD-ROM), a digital versatile disc (DVD), etc., a magneto-optical mediumsuch as a floptical disk, and a hardware device specially configured tostore and perform program instructions, for example, a read-only memory(ROM), a random access memory (RAM), a flash memory, etc. Examples ofthe computer instructions include not only machine language codegenerated by a compiler, but also high-level language code executable bya computer using an interpreter or the like. The hardware device may beconfigured to operate as one or more software modules in order toperform the operations of an embodiment, and vice versa.

According to an embodiment, there may be provided a method of correctingthe phase of a reconstruction signal in order to increase the resolutionof an image acquired by an image generation device, the method includingacquiring an initial phase correction value of an initial reconstructionsignal, acquiring a first phase correction value from the initial phasecorrection value on the basis of a first slope-based minimum searchtechnique, and acquiring a second phase correction value on the basis ofthe first phase correction value when a difference value between piecesof light information acquired for at least one pixel of an imageacquired based on a corrected reconstruction signal is less than orequal to a predetermined difference value. The image may be acquiredbased on the reconstruction signal and the light information, and thesecond phase correction value may be acquired from the first phasecorrection value on the basis of a second slope-based minimum searchtechnique, and the first slope-based minimum search technique may have adifferent phase search unit from the second slope-based minimum searchtechnique.

Also, when the first phase correction value is within a predeterminedrange from a first intermediate phase correction value found based onthe first slope-based minimum search technique and the reconstructionsignal is corrected with the first phase correction value, thereconstruction signal may have a higher fill factor when thereconstruction signal is corrected with the first phase correction valuethan when the reconstruction signal is corrected with the firstintermediate phase correction value.

Also, the fill factor may be a ratio of pixels, from which lightinformation is acquired based on an image reconstruction signal, to allpixels of the image acquired by the image generation device.

Also, the first phase correction value may differ from the initial phasecorrection value by an integer multiple of a predetermined phasedifference.

Also, the predetermined phase difference may be acquired based on afrequency component of the reconstruction signal.

Also, the first slope-based minimum search technique and the secondslope-based minimum search technique may include at least one of theNelder-Mead method, momentum method, AdaGrad method, Adam method,steepest gradient method, or gradient descent method.

Also, the first slope-based minimum search method and the secondslope-based minimum search method may enable the difference valuebetween the pieces of light information acquired for at least one pixelof the image to be minimized on the basis of the reconstruction signaland the phase of the reconstruction signal.

Also, the difference value between the pieces of the light informationmay be the variance of the pieces of light information acquired for atleast one pixel of the image.

Also, the difference value between the pieces of the light informationmay be the standard deviation of the pieces of light informationacquired for at least one pixel of the image.

Also, the phase search unit of the first slope-based minimum searchtechnique may be larger than the phase search unit of the secondslope-based minimum search technique.

Also, the first phase correction value and the initial phase correctionvalue of the reconstruction signal may be a tendency phase range in theentire phase range of the reconstruction signal.

Also, the tendency phase range may be a range in which the differencevalue between the pieces of light information decreases as thedifference value between the pieces of light information acquired for atleast one pixel of the image in close proximity to the second phasecorrection value of the reconstruction signal approaches the secondphase correction value.

Also, there may be provided a computer-readable recording medium onwhich a program for executing the phase correction method of thereconstruction signal is recorded.

According to another embodiment, there may be provided an imagegeneration device configured to correct the phase of a reconstructionsignal to increase the resolution of an acquired image, the imagegeneration device including a controller configured to correct the phaseof the reconstruction signal, a light emitter configured to emit lightto an object, and a light receiver configured to receive informationregarding light returning from the object, wherein the controller mayacquire an initial phase correction value of an initial reconstructionsignal, the controller may acquire a first phase correction value fromthe initial phase correction value on the basis of a first slope-basedminimum search technique, and the controller may acquire a second phasecorrection value on the basis of the first phase correction value when adifference value between pieces of light information acquired for atleast one pixel of an image acquired based on a corrected reconstructionsignal is less than or equal to a predetermined difference value. Theimage may be acquired based on the reconstruction signal and the lightinformation, and the second phase correction value may be acquired fromthe first phase correction value on the basis of a second slope-basedminimum search technique, and the first slope-based minimum searchtechnique may have a different phase search unit from the secondslope-based minimum search technique.

According to an embodiment of the present invention, an image generatingdevice for obtaining an image of an object, comprising: a control moduleconfigured to generate a first signal having a first frequency componentand a first phase component for a first axis direction, and a secondsignal having a second frequency component and a second phase componentfor a second axis direction, an emitting unit configured to emit lightto the object using the first signal and the second signal; and a lightreceiving unit configured to obtain light receiving signal based onreturned light from the object, wherein the control module configured toobtain a first data set based on the first signal, the second signal andthe light receiving signal, wherein the first signal and the secondsignal correspond to a first domain, wherein the control moduleconfigured to obtain a third signal and a fourth signal, wherein thethird signal and the fourth signal correspond to a second domain,wherein the control module configured to obtain a second data set basedon the third signal and the fourth signal, wherein the first data setand the second data set are different, wherein the control moduleconfigured to obtain an adjusting value of the first data set based onthe second data set, wherein the control module configured to obtain athird data set based on adjusting the first data set using the adjustingvalue, and wherein the control module configured to obtain the image ofthe object base on the third data set.

Also, the adjusting value is obtained based on a symmetricity of thesecond data set.

Also, the symmetricity is obtained based on a difference value of thelight receiving signal obtained on at least one of a second domain pixelposition, which the second domain pixel position is determined based onthe third signal and the fourth signal.

Also, the difference value is obtained based on a summation of at leastone of the light receiving signal.

Also, the difference value is obtained based on a integration of atleast one of the light receiving signal which is obtained at a seconddomain image corresponding to a phase delayed component of the thirdsignal and the fourth signal at the second domain.

Also, the difference value is obtained based on a fixed phase delayedcomponent which corresponds to a phase delayed component of at least oneof the third signal or the fourth signal.

Also, the fixed phase delayed component is plural, and the adjustingvalue corresponds to a minimum difference value which is obtained amongthe difference value obtained based on the fixed phase delayedcomponent.

Also, a first phase adjusting value corresponds to the fixed phasedelayed component of the third signal, a second phase adjusting valuecorresponds to the fixed phase delayed component of the fourth signal,and the adjusting value includes the first phase adjusting value and thesecond adjusting value.

Also, the third data set is obtained based on adjusting the first signalby the first phase adjusting value and adjusting the second signal bythe second phase adjusting value.

Also, a third phase adjusting value is obtained based on the first phaseadjusting value on the second domain, and wherein a fourth phaseadjusting value is obtained based on the second phase adjusting value onthe second domain.

Also, the first domain corresponds to a sinusoidal function domain, andthe second domain corresponds to a domain which is homeomorphictransformation of the first domain.

Also, the second domain corresponds to a domain which is homeomorphictransformation of the first domain by a phase domain.

Also, the image which is obtained by the image generating device isobtained on the first domain.

Also, a position on the second domain which is based on the third signaland the fourth signal is repeated by a predetermined period.

According to an embodiment of the present invention, an image generatingmethod for obtaining an image of an object, comprising: generating afirst signal having a first frequency component and a first phasecomponent for a first axis direction, and a second signal having asecond frequency component and a second phase component for a secondaxis direction through a control module; obtaining light receivingsignal based on returned light from the object through a light receivingunit; obtaining a first data set based on the first signal, the secondsignal and the light receiving signal; wherein the first signal and thesecond signal correspond to a first domain, obtaining a third signal anda fourth signal, such that the third signal and the fourth signalcorrespond to a second domain; obtaining a second data set based on thethird signal and the fourth signal; wherein the first data set and thesecond data set are different, wherein the control module configured toobtain an adjusting value of the first data set based on the second dataset, wherein the control module configured to obtain a third data setbased on adjusting the first data set using the adjusting value, andwherein the control module configured to obtain the image of the objectbase on the third data set.

1. General Information about Image Generation Device

1.1. Image Generation Device

An image generation device that may be used to acquire an image of anobject will be described below. Here, the image generation device may bean optical device for which at least one of a reflection image, afluorescence image, or a transmission image of an object is acquired orprovided.

FIG. 1 is a schematic diagram showing a configuration of an imagegeneration device according to an embodiment.

Referring to FIG. 1 , an image generation device according to anembodiment may include a controller 110, a light generator 120, a driver130, a light receiver 140, and a display 160.

According to an embodiment, the image generation device may include adevice for generating an image using light, such as Light Detection andRanging (LiDAR), a laser scanner, or a confocal microscope.

The controller 110 may drive software, programs, or algorithms necessaryto generate and correct an image. In other words, the controller 110 mayreceive electrical signals and output electrical signals.

For example, the controller 110 may drive software or a program forgenerating an image or drive an algorithm for generating an image on thebasis of a data acquisition manner to be described below.

However, the use of the controller 110 is not limited to the aboveexample, and the controller 110 may drive software, programs, oralgorithms that can be executed by a typical computing device.

The light generator 120 may generate light in various wavelength bandsincluding infrared, ultraviolet, and visible rays. The light generatedby the light generator 120 may be emitted to an object.

For example, the light generated by the light generator 120 may be lighthaving a wavelength of 405 nm, 488 nm, or 785 nm to cause a fluorescentdye to emit light. However, the present invention is not limitedthereto, and the generated light may be light in a wavelength band forcausing a fluorescent material, which includes an autofluorescentbio-material present in an object, to emit light, for example, lighthaving a wavelength band for generating autofluorescence of cells.

Also, the light generated by the light generator 120 may be unamplifiedlight or light amplified by stimulated emission of radiation(hereinafter referred to as a laser beam).

The driver 130 may drive elements in a light traveling path to changethe path when the light generated by the light generator 120 is emittedto an object. In other words, the driver 130 may receive electric energyor an electric signal from the controller 110 and drive the elements inthe light traveling path. Here, the elements in the light traveling pathmay include a fiber 310 which serves as a light traveling passage and amicroelectromechanical systems (MEMS) mirror by which the lightgenerated by the light generator 120 is reflected.

For example, the driver 130 may be a driving element including anelectric motor, a magnetic motor, a piezoelectric element, or athermoelectric element. However, the present invention is not limited tothe above example, and the driver 130 may include an element capable ofgenerating kinetic energy when electric force or magnetic force isapplied,

According to an embodiment, the driver 130 may drive an element in thelight traveling path in at least one direction. That is, the driver 130may receive an electric signal and apply force to an element in thelight traveling path in at least one axis direction.

For example, when one axis is determined in a space where light isemitted to an object, the driver 130 may apply force in the direction ofthe axis and the direction of an axis perpendicular to the axis. Inother words, the driver 130 may drive an element in the light travelingpath in the direction of an axis and the direction of an axisperpendicular to the axis.

According to an embodiment, at least one of the light generator 120 orthe driver 130 may be represented as an emitting unit that emits light.

The light receiver 140 may transform optical energy of light returnedfrom an object into electrical energy and transfer the electrical energyto the controller 110. In other words, the light receiver 140 mayacquire information on light returned from an object in the form of anelectric signal. For convenience of the following description, the lightreceiver 140 acquiring information on light returned from an object inthe form of an electric signal and transferring the electric signal tothe controller 110 will be described as the controller 110 acquiringlight information, but this does not mean that the controller 110directly acquires light information but that the light informationacquired by the light receiver 140 is transferred to the controller 110as described above. Likewise, the light receiver 140 acquiring lightinformation may also mean that the light receiver 140 transforms opticalenergy into electrical energy.

Also, the light information which will be described below may includelight intensity, light location information, and time informationrelated to a light acquisition time of a unit expressing the color oflight such as black and white, RGB, and CMYK. However, for convenienceof description, the term “light information” used herein may refer tolight intensity.

Here, the light receiver 140 may include an imaging element, alight-receiving element, a photographing device, a light receiver, alight detector, or a light-receiving device for acquiring lightinformation. For example, the light receiver 140 may include acharge-coupled device (CCD), a complementary metal-oxide semiconductor(CMOS), a photomultiplier tube (PMT), or a photodiode. However, thelight receiver 140 is not limited to the above example, and any elementmay be included in the light receiver 140 as long as the element cantransfer optical energy into electrical energy.

The display 160 may display an image generated by the controller 110 inan identifiable form. In other words, the display 160 may receive animage generated by the controller 110 and display the image so that theimage can be identified by a user.

For example, the display 160 may include an image display elementincluding a cathode ray tube (CRT), a liquid crystal display (LCD), alight-emitting diode (LED), or a liquid crystal on silicon (LCoS).However, the display 160 is not limited to the above example, and anydevice may be included in the display 160 as long as the device canreceive an electrical signal and display an image.

According to another embodiment, the image generation device may beprovided such that the display 160 is not included. That is, referringto FIG. 1 , it is shown that the display 160 is included in the imagegeneration device. However, the present invention is not limitedthereto, and the image generation device may include only the controller110, the light generator 120, the driver 130, and the light receiver140.

FIG. 2 includes diagrams showing a pattern in which light is emitted anda pattern which is for image reconstruction according to an embodiment.In other words, an electric signal that is input to the driver 130 bythe controller 110 or a reconstruction signal used that is used for thecontroller 110 to reconstruct an image may exhibit a specific pattern.

(a) of FIG. 2 shows a spiral pattern, (b) of FIG. 2 shows a rasterpattern, and (c) of FIG. 2 shows a Lissajous pattern.

According to an embodiment, when light is emitted to an object, theimage generation device may emit the light to the object such that thepath of the emitted light follows a specific pattern. In other words,when the paths of the light emitted to the object overlap during aspecific time, the light traveling path may exhibit a specific pattern.Here, the specific time for the overlapping may refer to a time taken tocomplete the pattern.

Referring to FIG. 2 , the light may be emitted to the object indifferent patterns depending on the electric signal input to the driver130. For convenience of the following description, light being emittedto an object may be expressed as the scanning of an object or thescanning of an object with light.

For example, referring to (a) of FIG. 2 , when the amplitude of theelectric signal input to the driver 130 is changed, the path of thelight emitted to the object may exhibit a spiral pattern.

Also, for example, referring to (b) of FIG. 2 , it is assumed that theelectric signal input to the driver 130 includes a first driving signalfor driving the driver 130 or an element in the light traveling path inone axis direction and a second driving signal for driving the driver130 or an element in the light traveling path in a directionperpendicular to the axis direction. When the frequency of the firstdriving signal and the frequency of the second driving signal differ byan integer multiple, the path of the light emitted to the object mayexhibit a raster pattern.

Also, for example, referring to (c) of FIG. 2 , it is assumed that theelectric signal input to the driver 130 includes a first driving signalfor driving the driver 130 or an element in the light traveling path inone axis direction and a second driving signal for driving the driver130 or an element in the light traveling path in a directionperpendicular to the axis direction. When the frequency of the firstdriving signal and the frequency of the second driving signal aredifferent from each other, the path of the light emitted to the objectmay exhibit a Lissajous pattern.

According to another embodiment, when the controller 110 of the imagegeneration device acquires light information through the light receiver140, a reconstruction signal for reconstructing an image using theacquired light information may exhibit a specific pattern. Here, thereconstruction signal exhibiting a specific pattern may mean that thecorresponding pattern is shown in the image actually reconstructed basedon the reconstruction signal, or that a signal for forming theaforementioned specific pattern is the reconstruction signal althoughthere is actually nothing shown in the image.

According to another embodiment, the pattern of the driving signal fordriving the driver 130 and the pattern of the reconstruction signal forreconstructing the image may be the same. In other words, the signalthat is input to the driver 130 by the controller 110 and the signalthat is used for the controller 110 to reconstruct the image may be thesame.

According to another embodiment, when there is a phase delay, thepattern of the driving signal for driving the driver 130 and the patternof the reconstruction signal for reconstructing the image may bedifferent.

For example, the path of light that is actually emitted to an object maybe different from the pattern of the driving signal, and thus thereconstruction signal may be a signal exhibiting a pattern forreflecting the path of the light that is actually emitted to the object.In other words, the reconstruction signal may be a signal that iscorrected to generate a pattern identical or similar to the pattern inwhich the light is actually emitted to the object. The correction of thereconstruction signal will be described in detail in the followingrelated section.

In the following description, a Lissajous pattern is to be used by theimage generation device. However, as described in the above embodiments,various patterns may be used by the image generation device.

1.1.1. General Information about Image Generation Device Using Fiber310.

According to an embodiment, an image generation device in which a pathtraveled by light generated by a light generator of the image generationdevice is an optical fiber 310 (hereinafter referred to as a fiber 310).In other words, an image generation device in which the above-describedelement in the light traveling path is the fiber 310 may be provided.

(a) of FIG. 3 is a schematic diagram showing a portion of an imagegeneration device including a driver 130 and a fiber 310 according to anembodiment, and (b) of FIG. 3 is a cross-sectional view of the driver130 and the fiber 310 when viewed from the front.

Referring to (a) of FIG. 3 , at least a portion of the fiber 310 may behoused in at least a portion of the driver 130. In other words, at leasta portion of the fiber 310 may be coupled to the driver 130.

Thus, when the driver 130 receives an electric signal from thecontroller 110 and then is driven, the fiber 310 may be driven such thata light traveling path exhibits a specific pattern in a certain area ofan object.

As a specific example, when light generated by the light generator 120is emitted to an object, the driver 130 receives an electric signalcapable of generating a Lissajous pattern and then is driven such that apath of the fiber 310 pointing to the object is the Lissajous pattern.

Although not shown in (a) of FIG. 3 , an additional attachment may beattached to the fiber 310. For example, the additional attachment may bea mass for increasing an amplitude in which the fiber 310 is driven or astructure attached onto the fiber 310 and configured to separate theresonance frequency of the fiber 310 in at least one direction.

Referring to (b) of FIG. 3 , the fiber 310 and elements of the driver130 according to an embodiment may be provided.

For example, referring to (b) of FIG. 3 , the driver 130 may include afirst-axis driving element, a second-axis driving element, and aninsulating element. Here, the first-axis driving element and thesecond-axis driving element may be separated by an insulating strip 132,and each of the driving elements may be composed of a set of one or moredriving elements. In other words, the first-axis driving element mayinclude at least one driving element to drive the driver 130 or thefiber 310 in a first-axis direction, and the second-axis driving elementmay include at least one driving element to drive the driver 130 or thefiber 310 in a second-axis direction. Here, the first axis and thesecond axis may be one axis determined in a plane where an object isscanned and an axis perpendicular to the axis. That is, in the planewhere the object is scanned, the first axis may refer to an x-axis, andthe second axis may be a y-axis. Conversely, the first axis may be ay-axis, and the second axis may be an x-axis.

1.1.2. General Information about Image Generation Device not Using Fiber310

According to an embodiment, an image generation device in which anelement in a path traveled by light generated by the light generator 120of the image generation device is not a fiber 310 may be provided. Inother words, when light is emitted to an object, an image generationdevice that emits the light to the object in a specific pattern may beprovided.

For example, an image generation device in which an element in a pathtraveled by light generated by the light generator 120 is a mirror maybe provided. In detail, when the light generated by the light generator120 is incident on the mirror through a light transmission mediumincluding air, vacuum, or the like, the mirror reflects the light anddirects the light to the object. Here, the mirror capable of reflectinglight may include an element formed of a material capable of directinglight, such as a MEMS mirror.

According to another embodiment, an image generation device in which anelement in a path traveled by light generated by a light generator 120is a light receiver 140 may be provided.

For example, when light is emitted to an object and returned from theobject, the light receiver 140 may be driven by the driver 130.Specifically, the light receiver 140 may be driven such that a path of apixel from which light information is acquired is a specific pattern.

1.2. Data Acquisition Method of Image Generation Device

A method of acquiring data including light information acquired throughthe light receiver 140 of the image generation device will be describedbelow.

FIG. 4 is a flowchart illustrating a method of an image generationdevice acquiring data for reconstructing an image according to anembodiment.

Referring to FIG. 4 , the method of the image generation deviceacquiring data for reconstructing an image may include acquiring lightinformation and time information (S1000), acquiring coordinateinformation based on the time information (S1200), applying lightinformation to the coordinate information (S1400), and acquiring animage (S1600).

FIG. 5 is a table schematically showing light information acquiredaccording to time information.

However, the following tables of the data acquisition method and datastorage method shown in FIGS. 5, 6, 17, and 23 are schematically writtenfor convenience of description, and actually, data may be acquired asdescribed in the tables. However, this does not mean that actuallystored or acquired data conforms to the table format.

Referring to FIGS. 4 and 5 , the operation of acquiring the lightinformation and acquiring the time information (S1000) may includeacquiring the time information at the same time a controller 110acquires the light information through a light receiver 140.

Alternatively, referring to FIGS. 4 and 5 , the operation of acquiringthe light information and acquiring the time information (S1000) mayinclude a controller 110 acquiring the time information based on apredetermined time interval, acquiring the light information based on apredetermined time interval, and correlating the acquired timeinformation with the acquired light information regardless of whetherthe light receiver 140 acquires the light information.

Here, the acquired time information may be acquired in proportion to thenumber of pieces of light information. That is, when n pieces of lightinformation are acquired from the light receiver 140, the controller 110may acquire n pieces of time information. Here, n may be an integergreater than or equal to one.

For example, referring to FIG. 5 , when the pieces of light informationacquired by the controller 110 are sequentially i1, i2, and i3 and thepieces of light information are acquired at t1, t2, and t3, thecontroller 110 may acquire or store data indicating that i1 is acquiredat time t1, i2 is acquired at time t2, and i3 is acquired at time t3.

FIG. 6 is a table schematically showing light information correspondingto coordinate information according to an embodiment.

Referring to FIGS. 4 and 6 , the operation of acquiring the coordinateinformation on the basis of the time information (S1200) may includederiving the coordinate information using the acquired time information.In other words, the coordinate information may be acquired by apredetermined relationship between the time information and thecoordinate information. The predetermined relationship may be thecoordinate information or a reconstruction signal for reconstructing animage.x=A _(x) sin(f _(x) t+φ _(x)), y=A _(y) sin(f _(y) t+φ _(y))  [Equation1]

Equation 1 is an equation representing a reconstruction signal that canbe used to convert time information into coordinate information and adriving signal that is for determining a pattern in which light isemitted to an object according to an embodiment.

Referring to Equation 1, x represents first-axis coordinate information,A_(x) is first-axis amplitude and represents the amplitude of thedriving signal or the reconstruction signal in the first axis, f_(x) isa first-axis frequency and represents the frequency of the drivingsignal or the reconstruction signal in the first axis, t represents timeinformation, and φ_(x) is a first-axis phase and represents the phase ofthe driving signal or the reconstruction signal in the first axis. Also,in Equation 1, y represents second-axis coordinate information, A_(y) issecond-axis amplitude and represents the amplitude of the driving signalor the reconstruction signal in the second axis, f_(y) is a second-axisfrequency and represents the frequency of the driving signal or thereconstruction signal in the second axis, t represents time information,and φ_(y) is a second-axis phase and represents the phase of the drivingsignal or the reconstruction signal in the second axis.

Hereinafter, for convenience of description, a signal indicating thefirst-axis coordinate information and the first-axis signal may beinterchangeably used, and a signal indicating the second-axis coordinateinformation and the second-axis signal may be interchangeably used.

Also, here, the unit of the phase may be a time, a frequency domain, ora radian. However, the present invention is not limited thereto, and allunits capable of expressing phases may be the unit of the phase.

Referring to FIG. 6 and Equation 1, the coordinate information acquiredby the controller 110 may refer to coordinate information in a Cartesiancoordinate system. However, the present invention is not limitedthereto, and the coordinate information that may be acquired by thecontroller 110 may include coordinate information in a polar coordinatesystem, 3-dimensional coordinate information, 4-dimensional coordinateinformation, coordinate information in a spherical coordinate system,coordinate information in a cylindrical coordinate system, coordinateinformation in a torus coordinate system, etc. However, the coordinatesystem used for the coordinate information does not refer to acoordinate system in one domain. When variables included in thecoordinate system are present in different domains, the same coordinatemay be used. For example, a Cartesian coordinate system may be used whentime and intensity are used as variables or when frequency and intensityare used as variables.

For example, referring to FIG. 5 , FIG. 6 , and Equation 1, coordinateinformation including the first-axis coordinate information and thesecond-axis coordinate information may be acquired from time informationacquired by the controller 110.

As a specific example, it is assumed that the time information is t1 andthe acquired light information is t1. When t1 is substituted for areconstruction signal capable of converting the time information intothe coordinate information, the controller 110 may acquire x1, which isthe first-axis coordinate information, and y1, which is the second-axiscoordinate information. In other words, when the time informationacquired by the controller 110 is t1, the controller 110 may acquire x1and y1, which are pieces of coordinate information that can representone point in a two-dimensional plane, from the time information t1.Likewise, when the time information acquired by the controller 110 is t2and t3, the controller 110 may acquire x2 and y2, which correspond tothe time information t2, and x3 and y3, which correspond to the timeinformation t3. Here, when the number of pieces of time informationacquired by the controller 110 is n, the controller 110 may acquire npieces of first-axis coordinate information (x) and n pieces ofsecond-axis coordinate information (y) according to the timeinformation.

Referring to FIGS. 4 and 6 , the operation of applying the lightinformation to the coordinate information (S1400) may include the aboveoperation of the controller 110 applying the acquired light informationto the coordinate information acquired through the time information onthe basis of the reconstruction signal.

However, referring to FIG. 4 , the operation of acquiring the coordinateinformation on the basis of the time information (S1200) and theoperation of applying the light information to the coordinateinformation (S1400) may be shown as separate operations. However, thepresent invention is not limited thereto, and the light information maybe substituted while acquiring the coordinate information. In otherwords, among the data regarding the acquired time information and lightinformation, the controller 110 may change only the time informationinto the coordinate information. Accordingly, the light information isnot actually substituted for the acquired coordinate information, andthe time information is changed to the coordinate information. Thus, thelight information may correspond to the coordinate information.Hereinafter, the light information corresponding to the coordinateinformation or the time information is expressed as the substitution ofthe light information for the time information or the coordinateinformation.

FIG. 7 is a schematic diagram showing light information acquired foreach pixel of an image to reconstruct an image according to anembodiment.

However, the reconstructed image and the schematic diagram of the pixelupon the image reconstruction in addition to FIG. 7 are just used forconvenience of the following description and may refer not to theprovision of an actual image but to a state of only the lightinformation and the coordinate information being acquired.

Referring to FIGS. 4 and 7 , the operation of acquiring the image(S1600) includes reconstructing the image on the basis of the acquiredcoordinate information and light information.

Here, the acquired coordinate information may correspond to pixelinformation of the reconstructed image. In other words, the coordinateinformation may be the same as pixel information, or the pixelinformation may be derived from the coordinate information. In thiscase, the pixel information may refer to location information includingcoordinate information of a pixel in an image.

Also, a pixel which will be described below may be a unit for expressinglight information in an image. In other words, an image acquired by thecontroller 110 may include a plurality of pixels for representing thelight information. Here, the size of the unit pixel may be determinedbased on the predetermined number of pixels and the size of the acquiredimage. Likewise, the number of unit pixels may be determined based onthe size of the pixels and the size of the acquired image.

Also, the acquired image may have various resolutions. For example, theacquired image may have various resolutions including 256×256, 512×512,1024×1024, 800×600 (SVGA), 1024×768 (XGA), 1280×800 (WXGA), 1920× 1080(FHD), 1920×1200 (WUXGA), 2560× 1440 (QHD), 3840×2160 (UHD (4K)), or7680×4320 (UHD (8K)). However, the present invention is not limitedthereto, and when a plurality of pixels for displaying an image areincluded, the resolutions of the image acquired by the controller 110may include a resolution corresponding to the pixels. Theabove-described resolution may refer to the actual number of pixels.However, the present invention is not limited thereto, and theresolution may refer to the number of pixels on the basis of parts perinch (PPI).

For example, referring to FIG. 7 , the acquired image may include npixels in the first axis and include m pixels in the second axis. Inthis case, the light information may be substituted for the pixelinformation corresponding to the acquired coordinate information.Accordingly, when the light information is substituted for the pluralityof pixels, the controller 110 may acquire an image of an object.

In this case, when the phase or the like of a reconstruction signal forreconstructing the coordinate information is different from that of asignal forming a pattern in which light is actually omitted to theobject, the acquired image may be distorted and provided. Accordingly,the phase correction of the reconstruction signal may be required andwill be described in detail below in the following related section.

2. Generation of Image Using Scanning Pattern

A method of generating an image using a scanning pattern will bedescribed below. Here, an acquired image may be an image for a singlemoment, or the acquisition of one frame in a continuous video of anobject may be expressed as the acquisition of the image.

In other words, when images are continuously acquired from an object,the controller 110 may acquire a video of the object.

FIG. 8 is a flowchart illustrating a method of acquiring one frame sothat an image is acquired according to an embodiment.

Referring to FIG. 8 , the method of acquiring one frame may includeacquiring one frame after a predetermined time (S2000) and acquiring animage (S2200).

According to an embodiment, the operation of acquiring one frame afterthe predetermined time (S2000) may include the controller 110 acquiringone frame every predetermined time.

According to another embodiment, the operation of acquiring one frameafter the predetermined time (S2000) may include the controller 110acquiring one frame every unit time in which a scanning pattern isrepeated on the basis of the scanning pattern being repeated after thepredetermined time.

According to another embodiment, the operation of acquiring one frameafter the predetermined time (S2000) may include the controller 110acquiring one frame before the scanning pattern is repeated.

Here, the scanning pattern may be the pattern in which the light isemitted to the object or may refer to the pattern of the reconstructionsignal for reconstructing the image.

Also, the controller 110 acquiring one frame may mean that thecontroller 110 acquires time information, coordinate information, andthe light information every predetermined time. Alternatively, thecontroller 110 acquiring one frame may mean that the controller 110acquires the image on the basis of the acquired time information,coordinate information, and light information. Alternatively, thecontroller 110 acquiring one frame may mean that the controller 110designates data for generating an image on the basis of timeinformation, coordinate information, and light information for acquiringthe image as data for one frame.

According to another embodiment, additionally, the controller 110 mayacquire an image using coordinate information acquired for pixelinformation or light information corresponding to the coordinateinformation.

In other words, the controller 110 does not substitute new coordinateinformation or light information corresponding to the coordinateinformation for all pixel information every frame after one frame isacquired once. Instead, whenever coordinate information or lightinformation corresponding to the coordinate information is acquired forcorresponding pixel information, the controller 110 may substitute thelight information for the corresponding pixel information. That is, foreach piece of pixel information, the light information may be updatedfor each pixel regardless of whether one frame is acquired.

Here, the light information being updated may mean that a value of thelight information substituted for the corresponding pixel information ischanged to newly acquired light information.

Conditions for the controller 110 to acquire one frame will be describedin detail in the following related section.

The operation of acquiring the image (S2200) may be identical to theoperation of acquiring the image (S1600) shown in FIG. 4 . In otherwords, the operation of acquiring the image (S2200) may be an operationof the controller 110 acquiring and providing an image of an object.

2.1. Frequency Selection for Image Generation

A method of the controller 110 selecting a frequency of a reconstructionsignal or a driving signal so as to minimize coordinate information orpixel information for which light information is not substituted will bedescribed below.

FIG. 9 is a diagram showing that the form of a pattern changes alongwith the change in frequency of a signal that generates the patternaccording to an embodiment.

According to an embodiment, the controller 110 may acquire differentpattern shapes depending on the selection of a first-axis frequency anda second-axis frequency and the difference between a first-axis phaseand a second-axis phase. In other words, a fill factor (hereinafterreferred to as FF) which indicates the occupancy portion of a specificarea may vary depending on the selection of a first-axis frequency and asecond-axis frequency and the difference between a first-axis phase anda second-axis phase. Here, FF may be expressed as a percentage or may beexpressed as having a value between 0 and 1.

Referring to Equation 1 again, the first-axis frequency and thesecond-axis frequency may refer to f_(x) and f_(x) of the reconstructionsignal or the driving signal, respectively.

Here, FF may refer to a ratio of the area to which light is actuallyemitted to the area of a scanned object.

Alternatively, FF may refer to a ratio of the number of pixels fromwhich coordinate information or pixel information is acquired by thereconstruction signal to the total number of pixels of the acquiredimage. In other words, FF may refer to a ratio of the number of pixelsfrom which light information is actually acquired to the total number ofpixels of the acquired image.

Accordingly, when the acquired image is reconstructed, the controller110 may acquire an image with a substantially high resolution when theFF is high. Here, this may mean that light information is acquired formore pixels in the image with the substantially high resolution than inan image with a low resolution. In other words, the image with thesubstantially high resolution may refer to an image with better quality.

As a specific example, referring to FIG. 9 , (a) of FIG. 9 is a diagramshowing a case in which the first-axis frequency is 4 Hz and thesecond-axis frequency is 6 Hz, (b) of FIG. 9 is a diagram showing a casein which the first-axis frequency is 7 Hz and the second-axis frequencyis 8 Hz, and (c) of FIG. 9 is a diagram showing a case in which thefirst-axis frequency is 16 Hz and the second-axis frequency is 19 Hz.

Here, referring to FIG. 9 , when the first-axis frequency and thesecond-axis frequency are in similar bands, FF may increase as thegreatest common divisor (GCD) of the first-axis frequency and thesecond-axis frequency decreases.

As a specific example, referring to (a) and (b) of FIG. 9 , the GCD ofthe first-axis frequency and the second-axis frequency of (a) of FIG. 9is two and the GCD of the first-axis frequency and the second-axisfrequency of (b) of FIG. 9 is one. Thus, the pattern of (b) of FIG. 9has a greater FF than the pattern of (a) of FIG. 9 .

Also, referring to FIG. 9 , FF may increase as the first-axis frequencyor the second-axis frequency is set to be high.

As a specific example, referring to (b) and (c) of FIG. 9 , both of theGCD of the first-axis frequency and the second-axis frequency of (b) ofFIG. 9 and the GCD of the first-axis frequency and the second-axisfrequency of (c) of FIG. 9 are one, but the band of the first-axisfrequency and the second-axis frequency of (c) of FIG. 9 is set to behigher than the band of the first-axis frequency and the second-axisfrequency of (b) of FIG. 9 . Thus, the pattern of (c) of FIG. 9 may havea greater FF than the pattern of (b) of FIG. 9 .

Here, the first-axis frequency and the second-axis frequency set for thedriving signal or the reconstruction signal may be set based on theresonant frequency of the fiber 310 of the image generation device sothat the fiber 310 can be resonantly driven.

3. Image Correction

A method of the controller 110 correcting the phase of a reconstructionsignal for reconstructing coordinate information or pixel informationwhen an image is distorted because the phase of the reconstructionsignal is different from the phase of a signal forming a pattern inwhich light is actually emitted to an object will be described below.

Here, the correction of the phase of the reconstruction signal mayinclude the controller 110 reflecting a phase correction value in thereconstruction signal and acquiring coordinate information on the basisof the reconstruction signal in which the phase correction value isreflected.

In the present application, for convenience of description, the term“correction” used herein may refer to calibration.

3.1. General Information about Image Correction

FIG. 10 is a flowchart illustrating a method of an image generationdevice acquiring data in which the phase of a reconstruction signal iscorrected according to an embodiment.

Referring to FIG. 10 , the method of the controller 110 acquiring animage in which the phase of a reconstruction signal is corrected mayinclude acquiring light information and time information (S1000),acquiring coordinate information based on the time information (S1200),applying the light information to the coordinate information (1400),acquiring a phase correction value and correcting the phase of areconstruction signal (S1500), and acquiring an image (S1600).

Referring to FIGS. 4 and 10 above, the method of acquiring data in whicha phase is corrected may include the operation of acquiring a phasecorrection value and correcting the phase of a reconstruction signal(S1500) in addition to the method of the image generation deviceacquiring image reconstruction data which is shown in FIG. 4 .

In order to reduce distortion of the image acquired by the controller110, the operation of acquiring the phase correction value andcorrecting the phase of the reconstruction signal (S1500) may includecorrecting the phase of the reconstruction signal using artificialintelligence based on deep learning or neural network learning or usinga phase correction algorithm or the like such that coordinateinformation or pixel information acquired based on the reconstructionsignal is corrected.

FIG. 11 includes diagrams showing an original image of an object and animage of the object reconstructed based on a reconstruction signal witha phase delay according to an embodiment.

Specifically, (a) of FIG. 11 is a diagram showing that an image of anobject is acquired based on a reconstruction signal with a phase delay,and (b) of FIG. 11 is a diagram showing that an image of an object isacquired based on a reconstruction signal with no phase delay.

Here, the phase of the reconstruction signal being delayed may mean thatthe phases of the first-axis signal and the second-axis signal forming apattern generated when light is emitted to an object on the basis of adriving signal are different from the phases of the first-axis signaland the second-axis signal of the reconstruction signal. That is, thephase of the reconstruction signal not being delayed may mean that thepattern in which the light is emitted to the object is identical orsimilar to the pattern which is based on the reconstruction signal.

In other words, the phase of the reconstruction signal being delayed maymean that when coordinate information or pixel information is acquiredbased on the reconstruction signal, light information is acquired incoordinate information or pixel information other than coordinateinformation or pixel information acquired based on the reconstructionsignal with no phase delay.

FIG. 12 is a table schematically showing coordinate information andlight information corresponding to the coordinate information on thebasis of a reconstruction signal with a phase delay according to anembodiment.

For example, referring to FIGS. 6 and 12 , FIG. 6 shows coordinateinformation acquired based on a reconstruction signal with no phasedelay and light information corresponding to the coordinate information,and FIG. 12 shows coordinate information acquired based on areconstruction signal with a phase delay and light informationcorresponding to the coordinate information. Here, when lightinformation acquired in a coordinate x1, which is one piece offirst-axis coordinate information, and a coordinate y1, which is onepiece of second-axis coordinate information, is based on areconstruction signal with no phase delay, i1, which is one piece of thelight information, may be acquired. On the other hand, when the lightinformation is based on a reconstruction signal with a phase delay, i2may be acquired. That is, when the phase of the reconstruction signal isdelayed, different light information may be acquired in coordinateinformation indicating the same coordinate as that when the phase of thereconstruction signal is not delayed.

As described above, since the phase of the reconstruction signal isdelayed for a predetermined reason, light information for reconstructingan image cannot be acquired at original coordinates where the lightinformation should have been acquired but may be acquired at differentcoordinates.

Here, the phase of the reconstruction signal may be delayed because theactual driving signal and a signal by which the fiber 310 is driven aredifferent from each other. Alternatively, the phase of thereconstruction signal may be delayed due to movement caused by a useractually operating the image generation device. Alternatively, the phaseof the reconstruction signal may be delayed due to the difference intime until light returned from an object is acquired by the lightreceiver 140. Alternatively, when the driver 130 is to be driven by adriving signal, the phase of the reconstruction signal may be delayedbecause the driver 130 is not actually driven by the driving signal. Inaddition to the above example, the phase of the reconstruction signalmay be delayed due to physical characteristics resulting from the driver130, the fiber 310, and the light receiver 140.

Also, image distortion may occur in addition to the delay of thereconstruction signal.

FIG. 13 is a schematic diagram showing that a mechanical coupling (MC)phenomenon occurs when the fiber 310 is driven according to anembodiment.

Here, the MC phenomenon may mean that the bands of the first-axisfrequency and the second-axis frequency of the driving signal are notsufficiently separated and that when the fiber 310 is driven in thefirst axis, the fiber 310 is also driven in the second axis.

Here, an ellipse shown in FIG. 13 may indicate the movement of an end ofthe fiber 310 or may indicate a trace of light emitted to an object.

Specifically, (a) of FIG. 13 may show a trace of light at an object oran end of the fiber 310 when the driver 130 drives the fiber 310 only inthe first axis according to an embodiment. Also, (b) of FIG. 13 may showa trace of light at an object or an end of the fiber 310 when the driver130 drives the fiber 310 only in the second axis according to anembodiment.

According to an embodiment, even when the driver 130 drives the fiber310 only in one axis, the fiber 310 may be driven in another axis. Here,when the driver 130 drives the fiber 310 in one axis but the fiber 310is driven in another axis, this may mean that an MC phenomenon hasoccurred.

For example, referring to (a) and (b) of FIG. 13 , an axis in which thedriver 130 intends to drive the fiber 310 may be an axis that is drivenin a range as much as R, but in practice, the fiber 310 may be driven bythe driver 130 in an axis direction with an unintended range as much asr. In other words, the driver 130 may apply a signal or force to drivethe fiber 310 in the first axis or the second axis by the range R, butthe fiber 310 may be additionally driven in the second axis or the firstaxis by the range r.

This may mean that an MC phenomenon has occurred because the axis inwhich the driver 130 drives the fiber 310 is different from the axis inwhich the fiber 310 is resonantly driven. Alternatively, when frequencyseparation in the first axis and the second axis of the fiber 310 is notsufficiently performed, this may mean that an MC phenomenon hasoccurred.

When the MC phenomenon has occurred, a first-axis MC signal and asecond-axis MC signal are additionally acquired as the reconstructionsignal in addition to the first-axis signal and the second-axis signalto acquire coordinate information. In other words, in order for thereconstruction signal to be reconstructed into the signal forming thepattern in which the light is actually emitted to the object, thefirst-axis MC signal and the second-axis MC signal may need to beadditionally acquired in addition to the acquisition of the phase delayvalues of the first-axis signal and the second-axis signal.

Here, the first-axis MC signal may have the same frequency as thesecond-axis signal. Likewise, the second-axis MC signal may have thesame frequency as the first-axis signal. This is because, for example,when the MC phenomenon has occurred, the fiber 310 is driven in thefirst axis and the second axis even though a driving signal input by thedriver 130 is the first-axis signal.

Also, in addition to correcting the phase delays of the first-axissignal and the second-axis signal from an initial signal of thereconstruction signal, the controller 110 may set initial signals of thefirst-axis MC signal and the second-axis MC signal and correct the phasedelays of the first-axis MC signal and the second-axis MC signal. Thisis because the controller 110 can acquire an image by correcting thedifference with the pattern in which the light is actually emitted tothe object on the basis of the first-axis MC signal and the second-axisMC signal that are initially set.

Accordingly, apart from the phase delay, image distortion may occur whenan MC phenomenon occurs. The controller 110 may correct the delayedphase of the reconstruction signal or may correct the occurrence of anMC phenomenon on the basis of the reconstruction signal.

FIG. 14 is a flowchart illustrating a method of the controller 110performing phase correction according to an embodiment.

Referring to FIG. 14 , the method of the controller 110 performing phasecorrection may include acquiring an initial phase correction value(S4000) and acquiring a detailed phase correction value (S4200).

Here, the phase correction value may refer to a value for correcting thedelayed phase of the reconstruction signal. In other words, the phasecorrection value may be a value that is added to or subtracted from thephase of the reconstruction signal to correct the phase of thereconstruction signal.

Here, the method of the controller 110 performing phase correction maybe an operation that is included in or identical to the above operationof acquiring the phase correction value and correcting the phase of thereconstruction signal of FIG. 10 (1500).

The operation of acquiring the initial phase correction value (S4000)may include acquiring a phase approximately adjacent to the delayedphase of the reconstruction signal in the entire phase range of thereconstruction signal in order for the controller 110 to correct thedelayed phase of the reconstruction signal. Here, the phase adjacent tothe delayed phase of the reconstruction signal where the initial phasecorrection value is positioned may have different adjacent rangesdepending on the initial phase correction method.

The method of the controller 110 acquiring the initial phase correctionvalue will be described in detail in the following related section.

The operation of acquiring the detailed phase correction value (S4200)may include generating coordinate information by changing the phase ofthe reconstruction signal in order to actually acquire the delayed phasevalue of the reconstruction signal in the initial phase correction valueso that the controller 110 can correct the delayed phase of thereconstruction signal. Here, the detailed phase correction value may bethe same as or substantially the same as the actual phase delay value ofthe reconstruction signal.

In this case, the detailed phase correction value and the actual phasedelay value of the reconstruction signal being substantially the samemay mean that the detailed phase correction value is within an errorrange from the actual phase delay value of the reconstruction signal.Here, the error range may be determined by the quality of the imageacquired by the image generation device.

According to an embodiment, when the quality of the image provided bythe image generation device is high, the error range may be set to besmall. In other words, a search phase unit in which the controller 110searches in order to acquire the detailed phase correction value may beset to be small.

According to another embodiment, when the quality of the image providedby the image generation device is low, the error range may be set to belarge. In other words, a search phase unit in which the controller 110searches in order to acquire the detailed phase correction value may beset to be large.

In addition to the aforementioned embodiments, the controller 110 maysearch for the detailed phase correction value on the basis of a searchphase unit fixed to acquire the detailed phase correction value.

The controller 110 searching for the phase correction value may mean anoperation of acquiring a phase correction value which will be describedbelow.

3.2. Acquisition of Initial Phase Correction Value

The method of the controller 110 acquiring the initial phase correctionvalue will be described below.

However, the initial phase correction does not mean that the controller110 corrects the phase of the reconstruction signal only at the initialstage, and the controller 110 may acquire even the detailed phasecorrection value using the method of acquiring the initial phasecorrection value.

3.2.1. Type of Initial Phase Correction Method

According to an embodiment, a user of the image generation device maydirectly change the phase of the reconstruction signal to search for theinitial phase correction value.

For example, when a phase adjustment unit configured to adjust the phaseof the first-axis signal and the second-axis signal of thereconstruction signal is included in the image generation device, theuser may adjust the phase of the reconstruction signal using the phaseadjustment unit. Here, the controller 110 may generate coordinateinformation or pixel information on the basis of the phase of thereconstruction signal adjusted by the user using the phase adjustmentunit, and the display 160 may display an image on the basis of lightinformation and the coordinate information or pixel information.Accordingly, the user may acquire an image of an object while adjustingthe phase of the reconstruction signal using the phase adjustment unit.

According to another embodiment, a random search method may be used forthe controller 110 to perform the initial phase correction.

For example, the random search method may include a method of settingthe phase of the reconstruction signal to a plurality of arbitrary phasevalues and selecting a phase similar to each delayed phase of thereconstruction signal as an initial phase correction value.

Accordingly, the controller 110 may acquire a detailed phase correctionvalue on the basis of the selected initial phase correction value.

According to another embodiment, an exhaustive search (brute-forcesearch) method may be used for the controller 110 to perform the initialphase correction.

For example, the exhaustive search method may include a method of thecontroller 110 setting each phase of the reconstruction signal in theentire phase range of the reconstruction signal and selecting a phasesimilar to each delayed phase of the reconstruction signal as an initialphase correction value.

Also, according to another embodiment, the controller 110 may performinitial phase correction by acquiring coordinate information from aphase domain rather than acquiring coordinate information or the likefrom a sine function domain, which is a restoration signal format, inorder to perform the initial phase correction.

The method of the controller 110 acquiring the phase correction value ofthe reconstruction signal from the phase domain will be described indetail in the following related section.

In addition to the aforementioned embodiments, the controller 110 mayacquire the initial phase correction value on the basis of a convexitymethod using a tendency corresponding to a change in the phase value ofthe reconstruction signal, a minimum search method using artificialintelligence including machine learning or neural network learning, or aconventional algorithm for searching for the lowest value.

3.2.2. Orbifold Method

The method of the controller 110 performing initial phase correction byacquiring coordinate information from a phase domain according to anembodiment rather than acquiring coordinate information or the like froma sine function domain, which is a restoration signal format, in orderto perform the initial phase correction will be described below.

Here, the domain may refer to a dimension of a reconstruction signalused by the controller 110 to acquire coordinate information. In otherwords, the domain may refer to a space in which the controller 110arranges a reconstruction signal to acquire coordinate information.

According to an embodiment, the controller 110 may acquire thecoordinate information from the phase domain on the basis of theorbifold method and perform phase correction on the reconstructionsignal. Here, the orbifold method may mean that the phase correction isperformed in a domain other than the sine function domain of thereconstruction signal.

For example, when the reconstruction signal converts time informationinto coordinate information on the basis of a sine function includingtrigonometric functions, this may mean that the coordinate informationis acquired in the sine function domain, and the domain of thereconstruction signal may refer to the sine function domain.

The domain in which the correction phase value of the reconstructionsignal is acquired will be described below.

3.2.2.1. Domain in which Correction Phase Value is Acquired

According to an embodiment, the domain of the reconstruction signal maybe a sine function domain.

For example, referring to Equation 1 again, when the reconstructionsignal converts time information into coordinate information on thebasis of a sine function including trigonometric functions, this maymean that the coordinate information is acquired in the sine functiondomain, and the domain of the reconstruction signal may refer to thesine function domain.

According to another embodiment, the domain of the reconstruction signalmay be a phase domain.x′=A _(x)(f _(x) t+φ _(x)),(mod T) y′=A _(y)(f _(y) t+φ _(y))(modT)[Equation 2]

Equation 2 is an equation representing a reconstruction signal that isin the phase domain and that can be used to convert time informationinto coordinate information.

Referring to Equation 2, x′ represents first-axis phase domaincoordinate information obtained through conversion in the phase domain,A_(x) is first-axis amplitude and represents the amplitude of thedriving signal or the reconstruction signal in the first axis, f_(x) isa first-axis frequency and represents the frequency of the drivingsignal or the reconstruction signal in the first axis, t represents timeinformation, and φ_(x) is a first-axis phase, represents the phase ofthe driving signal or the reconstruction signal in the first axis, andrefers to a phase delay component in the first axis. Also, y′ representssecond-axis phase domain coordinate information obtained throughconversion in the phase domain, A_(y) is second-axis amplitude andrepresents the amplitude of the driving signal or the reconstructionsignal in the second axis, f_(y) is a second-axis frequency andrepresents the frequency of the driving signal or the reconstructionsignal in the second axis, t represents time information, and φ_(y) is asecond-axis phase, represents the phase of the driving signal or thereconstruction signal in the second axis, and refers to a phase delaycomponent in the second axis. Also, mod may refer to the modulusoperator, that is, the modulo operation, and T may refer to apredetermined period. That is, (mod T) may mean that phase domaincoordinate information is repeated every predetermined period. Referringto Equation 2 and referring to Equation 1 again, the reconstructionsignal of the phase domain may be acquired based on a frequency, timeinformation, and a phase which are used as variables of a sine functionin the reconstruction signal of the sine function domain. In otherwords, the reconstruction signal of the phase domain may have a linearfunction format, rather than a sine function format, with respect totime information.

Also, according to an embodiment, the first-axis phase domain coordinateinformation or the second-axis phase domain coordinate information ofEquation 2 may be repeated every certain period when the acquired timeinformation is increased. In other words, referring to Equation 2, thetime information is repeated to the initial value according to apredetermined period T when the level of the increased time informationexceeds the predetermined period. For example, when the predeterminedperiod T is 2π, the first-axis phase domain coordinate information orthe second-axis phase domain coordinate information may be repeated toan initial value every 2π, which is one period of the basic sinefunction. However, the present invention is not limited thereto, and thepredetermined period T may be designated as various periods 2π or 4π. Inaddition to the aforementioned embodiments, for example, the domain ofthe reconstruction signal may include various domains such as Fourierdomain, Laplace domain, and z-transform domain. Here, the Fourierdomain, the Laplace domain, and the z-transform domain of thereconstruction signal may be domains where the Fourier transform, theLaplace transform, and the z-transform are performed in a reconstructionfunction of the sine function domain, respectively.

FIG. 15 includes diagrams showing an image acquired according to adomain of a reconstruction signal according to an embodiment.

Specifically, (a) of FIG. 15 is a diagram showing that an image of anobject is acquired based on a reconstruction signal in the sine functiondomain, and (b) of FIG. 15 is a diagram showing that an image of anobject is acquired based on a reconstruction signal in the phase domain.

According to an embodiment, referring to FIG. 15 , the controller 110may acquire an image that uses coordinate information acquired in thesine function domain and an image that uses coordinate informationacquired in the phase domain. Here, the image acquisition may refer toan operation of acquiring coordinate information using thereconstruction signal and applying light information to each ofcoordinate information.

Here, the number of pieces of coordinate information acquired in thephase domain may be greater than the number of pieces of coordinateinformation acquired in the sine function domain.

For example, referring to Equation 1 and Equation 2 again, Equation 1represents the sine function domain of the reconstruction signal, andEquation 2 represents the phase domain of the reconstruction function.In this case, referring to Equation 2, the first-axis phase domaincoordinate information is a linear function with respect to timeinformation, and one piece of coordinate information may be acquired forone piece of time information. However, referring to Equation 1, thefirst-axis coordinate information is a sine function with respect totime information, and one piece of coordinate information may beacquired for two or more pieces of time information.

Accordingly, an image acquired by the controller 110 using thecoordinate information acquired in the phase domain may be provided in aform in which an image acquired by the controller 110 using thecoordinate information acquired in the sine function domain is symmetricvertically and horizontally.

Also, the coordinate information acquired in the phase domain is morethan the coordinate information acquired in the sine function domain. Asa specific example, the number of pieces of coordinate informationacquired in the phase domain may be four or more times the number ofpieces of coordinate information acquired in the sine function domain.

Also, since the coordinate information acquired in the phase domain isvertically and horizontally symmetric compared to the coordinateinformation acquired in the sine function domain, the number of piecesof pixel information acquired based on the coordinate informationacquired in the phase domain may be greater than the number of pieces ofpixel information acquired based on the coordinate information acquiredin the sine function domain.

As a specific example, when the number of pieces of pixel informationacquired in the sine function domain in each of the first axis and thesecond axis may be 512×512, the number of pieces of pixel informationacquired in the phase domain in each of the first axis and the secondaxis may be 1024×1024.

However, the present invention is not limited to the aforementionedexample, and the pixel information acquired in the phase domain may havevarious numbers of pixels. Specifically, the number of pixels may be512×512, 2048×2048, or 4096×4096. Alternatively, a user may arbitrarilyset the number of pieces of pixel information.

3.2.2.2. Phase Correction Method Using Orbifold Method

The method of the controller 110 correcting the phase of thereconstruction signal using the orbifold method according to anembodiment will be described below.

FIG. 16 includes diagrams showing an image of the phase domain in whichthe phase of a reconstruction signal is not delayed and an image inwhich the phase of a reconstruction signal is delayed by usingcoordinate information acquired in the phase domain.

According to an embodiment, referring to FIG. 16 , when thereconstruction signal has no phase delay, an image of the phase domainacquired using coordinate information acquired in the phase domain maybe symmetric with respect to the center of the image acquired in thephase domain.

In other words, when the reconstruction signal has a phase delay, theimage acquired in the phase domain may not be symmetric with respect tothe center of the image.

Accordingly, when a phase in which the image acquired in the phasedomain is symmetric is found using the coordinate information acquiredin the phase domain, the controller 110 may acquire the phase delayvalue of the reconstruction signal. In other words, the image acquiredbased on the coordinate information acquired in the phase domain issymmetric with respect to the centers of the first axis and the secondaxis of the phase domain coordinate information. However, in the case ofa reconstruction signal with a phase delay, the image acquired based onthe coordinate information acquired in the phase domain is symmetricwith respect to points other than the centers of the first axis and thesecond axis of the phase domain coordinate information. Accordingly,when a phase in which the image is symmetric with respect to positionsother than the centers is found, the controller 110 may acquire thephase delay value of the reconstruction signal.

FIG. 17 is a flowchart illustrating a method of the controller 110acquiring an initial phase correction value of a reconstruction signalon the basis of symmetry of phase domain coordinate informationaccording to an embodiment.

Referring to FIG. 17 , the method of the controller 110 acquiring theinitial phase correction value of the reconstruction signal may includean operation of the controller 110 applying light information to phasedomain coordinate information (S4020), an operation of the controller110 determining the symmetry of the phase domain coordinate information(S4040), and an operation of the controller 110 acquiring the initialphase correction value (S4060).

Here, the method of the controller 110 acquiring the initial phasecorrection value of the reconstruction signal may be included in oridentical to the operation of the controller 110 acquiring the initialphase correction value (S4000).

FIG. 18 is a table schematically showing light information acquired forcoordinate information acquired in the phase domain of a reconstructionsignal according to time information according to an embodiment.

According to an embodiment, referring to FIGS. 17 and 18 , the operationof the controller 110 applying the light information to the phase domaincoordinate information (S4020) may include the controller 110 acquiringcoordinate information in the phase domain of the reconstruction signalaccording to time information and acquiring light informationcorresponding to the acquired coordinate information.

Here, the controller 110 acquiring the coordinate information in thephase domain may mean that the controller 110 acquires time informationon the basis of a predetermined time interval and acquires coordinateinformation on the basis of the acquired time information regardless ofwhether the light receiver 140 acquires the light information.

For example, referring to Equation 2 again, the controller 110 mayacquire first-axis phase domain coordinate information and second-axisphase domain coordinate information obtained through conversion in thephase domain on the basis of the time information. Accordingly, thecontroller 110 may correlate the light information corresponding to thetime information with the coordinate information acquired in the phasedomain. In other words, the controller 110 may acquire data such thatthe light information is correlated with the coordinate informationacquired in the phase domain.

FIG. 19 includes graphs showing that light information for each piece ofcoordinate information is added up based on the coordinate informationacquired in the phase domain according to an embodiment.

Specifically, in (a) of FIG. 19 , the horizontal axis represents thefirst-axis phase domain coordinate information, and the vertical axisrepresents the sum of the light information. Also, in (b) of FIG. 19 ,the horizontal axis represents the second-axis phase domain coordinateinformation, and the vertical axis represents the sum of the lightinformation. However, the present invention is not limited thereto, andthe vertical axis may be the product of pieces of the light informationor the integral value of the light information corresponding to thephase domain coordinate information. For convenience of description, thefollowing description assumes that the vertical axis represents the sumof the light information.

Here, according to an embodiment, the sum of the light information mayrefer to the sum of at least one piece of light information acquired forphase domain coordinate information.

For example, when one piece of first-axis phase domain coordinateinformation is fixed, a plurality of pieces of light information maycorrespond to coordinate positions indicated by a fixed piece offirst-axis coordinate information and a plurality of unfixed pieces ofsecond-axis phase domain coordinate information, and at least one of thelight information may be added up. In other words, in a two-dimensionalCartesian coordinate system, the light information may be added up byfixing the x-axis and using at least one y-axis coordinate value in theentire range of the y-axis. Likewise, when the second-axis phase domaincoordinate information is fixed, the light information can be added upin the same way as previously mentioned.

According to another embodiment, the sum of the light information mayrefer to the average after at least one piece of light informationacquired for phase domain coordinate information is added up.

Referring to FIGS. 17 and 19 , the operation of the controller 110determining the symmetry of the phase domain coordinate information(S4040) may include a method of the controller 110 determining thesymmetry of specific phase domain coordinate information in thefirst-axis phase domain coordinate information or the second-axis phasedomain coordinate information.

Here, the symmetry may mean that light information, or the sum of lightinformation, acquired from coordinate information that is spaced thesame distance (the same coordinate information distance) from specificfirst-axis phase domain coordinate information or specific second-axisphase domain coordinate information or the sum of the light informationis the same or similar.

Also, the determination of the symmetry may mean that the symmetry isdetermined in a situation where the first and last values of thefirst-axis phase domain coordinate information or the second-axis phasedomain coordinate information are continuous. For example, x′1, which isthe first value of the first-axis phase domain coordinate information,and x′n, which is the last value of the first-axis phase domaincoordinate information, are continuous, and values at the same distancefrom x′ 1 may be x′2 and x′n, which are the next values of x′1.

According to an embodiment, in order to determine the symmetry of thephase domain coordinate information, the controller 110 may determinespecific first-axis phase domain coordinate information and specificsecond-axis phase domain coordinate information as a basis and performthe determination on the basis of the difference in the sum of the lightinformation in the coordinate information spaced the same distance fromthe specific first-axis phase domain coordinate information or thesecond-axis phase domain coordinate information.

Here, the controller 110 finding a difference value between the sums ofpieces of light information may mean that difference values between thesums of pieces of light information in a plurality of pieces of phasedomain coordinate information acquired by the controller 110 are addedup.

For example, referring to FIG. 18 , when x′1, x′2, x′3, x′4, and x′5,which are the first-axis phase domain coordinate information, aresequential in the coordinate information in the phase domain, thecontroller 110 may find the difference between the sum of lightinformation acquired for x′1 coordination information and the sum oflight information acquired for x′5 coordinate information with respectto x′3 and the difference between the sum of light information acquiredfor x′2 coordinate information and the sum of light information acquiredfor x′4 coordinate information. Accordingly, when the symmetry isrealized with respect to x′3 coordinate information, a difference valuebetween the sum of the light information of the x′1 coordinateinformation and the sum of the light information of the x′5 coordinateinformation and a difference value between the sum of the lightinformation of the x′2 coordinate information and the sum of the lightinformation of the x′4 coordinate information with respect to the x′3coordinate information may be smaller than those based on other phasedomain coordinate information.

Likewise, the aforementioned method of determining the symmetry of thefirst-axis phase domain coordinate information may be used to determinethe symmetry of the second-axis phase domain coordinate information.

According to another embodiment, in order for the controller 110 todetermine the symmetry of the phase domain coordinate information, thecontroller 110 may determine specific first-axis phase domain coordinateinformation or specific second-axis phase domain coordinate informationas a basis and integrate the sum of light information of coordinateinformation spaced the same distance from the specific first-axis phasedomain coordinate information or second-axis phase domain coordinateinformation.

Also, according to another embodiment, in order for the controller 110to determine the symmetry of the phase domain coordinate information,the controller 110 may determine specific first-axis phase domaincoordinate information or specific second-axis phase domain coordinateinformation as a basis and multiply the sum of light information ofcoordinate information spaced the same distance from the specificfirst-axis phase domain coordinate information or the specificsecond-axis phase domain coordinate information.

In the aforementioned embodiments, the specific first-axis phase domaincoordinate information or the specific second-axis phase domaincoordinate information may be predetermined coordinate information todetermine symmetry. In other words, coordinate information may bepredetermined as a basis for determining symmetry, and thus thecontroller 110 may determine the symmetry of each piece of coordinateinformation in the first-axis phase domain coordinate information andthe second-axis phase domain coordinate information. That is, thefirst-axis phase domain coordinate information or the second-axis phasedomain coordinate information for determining symmetry may be at leastone piece of coordinate information.

Referring to FIG. 17 , the operation of the controller 110 acquiring theinitial phase correction value (S4060) may include the controller 110acquiring the initial phase correction value on the basis of thesymmetry determined using the specific first-axis phase domaincoordinate information or the specific second phase domain coordinateinformation which is predetermined by the controller 110.

According to an embodiment, the controller 110 may determine thesymmetry of each piece of coordinate information, acquire specificfirst-axis phase domain coordinate information or specific second-axisphase domain coordinate information which is most symmetric, and acquirea phase corresponding to the acquired coordinate information as theinitial phase correction value of the reconstruction signal.

For example, when the sum of difference values between the sums ofpieces of light information acquired for coordinate information at thesame distance from the specific first-axis phase domain coordinateinformation is smallest, the controller 110 may acquire a phasecorresponding to the specific first-axis phase domain coordinateinformation as the initial phase correction value of the reconstructionsignal.

FIG. 20 is a flowchart illustrating the order in which an approximatephase correction value of an initial phase correction value is acquiredaccording to an embodiment.

Referring to FIG. 17 and FIG. 20 , the operation of the controller 110acquiring the approximate phase correction value of the initial phasecorrection value (S4100) may be performed by the controller 110 afterthe operation of the controller 110 acquiring the initial phasecorrection value (S4060). In other words, the operation of thecontroller 110 acquiring the approximate phase correction value of theinitial phase correction value (S4100) may be performed by thecontroller 110 before the operation of the controller 110 acquiring thedetailed phase connection value (S4200).

According to an embodiment, the operation of the controller 110acquiring the approximate phase correction value of the initial phasecorrection value (S4100) may include the controller 110 acquiringapproximate phase domain coordinate information close to the detainedphase correction value and a phase value corresponding to theapproximate phase domain coordinate information on the basis of theinitial phase correction value and the symmetry of the phase domaincoordinate information corresponding to the initial phase correctionvalue.

For example, referring to FIGS. 18 and 20 , when the first-axis phasedomain coordinate information corresponding to the initial phasecorrection value acquired by the controller 110 is x′2, approximatefirst-axis phase domain coordinate information corresponding to afirst-axis approximate phase correction value is approximated to ahorizontally symmetric function on the basis of coordinate informationof x′1, x′2, and x′3 and the sum of pieces of light information acquiredfor coordinate information, and the controller 110 may acquirefirst-axis phase domain coordinate information in which the sum of thelight information is equal or close to zero.

Here, for example, the horizontally symmetric function for approximationmay refer to a function that is horizontally symmetric at a point wherex is b as in y=a|x−b|+c. That is, when x′1, x′2, and x′3 and the sum ofthe light information corresponding to the coordinate information aresubstituted for x and y, b, which is approximate first-axis phase domaincoordinate information that is horizontally symmetric, may be acquired.Accordingly, an approximate phase correction value corresponding to theapproximate first-axis phase domain coordinate information may beacquired by the controller 110.

Also, approximate second-axis phase domain coordinate information and asecond-axis approximate phase correction value may be acquired in thesame manner as the method of acquiring the approximate first-axis phasedomain coordinate information and the first-axis approximate phasecorrection value.

According to an embodiment, the approximate phase correction valueacquired in the operation of the controller 110 acquiring theapproximate phase correction value of the initial phase correction value(S4100) may be used in the operation of the controller 110 acquiring thedetailed phase correction value (s4200).

3.2.2.3. Method of Correcting Mechanical Coupling Using Orbifold Method

FIG. 21 includes diagrams showing an image acquired when an MCphenomenon has occurred and an image acquired when an MC phenomenon hasnot occurred by using coordinate information acquired in the phasedomain according to an embodiment.

Specifically, referring to FIG. 21 , (a) of FIG. 21 is a diagram showingan image acquired based on phase domain coordinate information acquiredwhen there is no phase delay and no MC phenomenon occurs, and (b) ofFIG. 21 is a diagram showing an image acquired based on phase domaincoordinate information acquired when there is no phase delay but an MCphenomenon occurs.

According to an embodiment, based on the phase domain coordinateinformation, the controller 110 may acquire information on whether an MCphenomenon has occurred. When an MC phenomenon has occurred, thecontroller 110 may correct the MC phenomenon on the basis of lightinformation corresponding to the phase domain coordinate information.

In other words, the controller 110 may acquire a first-axis MC signaland a second-axis MC signal on the basis of the light informationacquired in the phase domain coordinate information.

For example, when the controller 110 acquires the phase of thefirst-axis MC signal and the phase of the second-axis MC signal on thebasis of the phase domain coordinate information, the controller 110 mayreconstruct an image in consideration of the first-axis MC signal andthe second-axis MC signal as reconstruction signals in addition to thefirst-axis signal and the second-axis signal.

Here, in order to acquire the first-axis MC signal and the second-axisMC signal, the controller 110 may perform a computing operation on thebasis of a rotation matrix that uses the phases of the first-axissignal, the second-axis signal, the first-axis MC signal, and thesecond-axis MC signal as variables. Also, the controller 110 may acquirethe phases of the first-axis signal, the second-axis signal, thefirst-axis MC signal, and the second-axis MC signal as a result of thecomputing operation.

3.3. Acquisition of Detailed Phase Correction Value

The method of the controller 110 acquiring the detailed phase correctionvalue will be described below.

However, in the case of detailed phase correction, the controller 110does not always acquire the detailed phase correction value for thephase of the reconstruction signal only after acquiring the initialphase correction value, and the controller 110 may perform the method ofacquiring the detailed phase correction value without acquiring theinitial phase correction value or may acquire the initial phasecorrection value using the method of acquiring the detailed phasecorrection value.

3.3.1. General Information about Detailed Phase Correction Method

FIG. 22 is a flowchart illustrating a method of the controller 110acquiring a detailed phase correction value according to an embodiment.

Specifically, referring to FIG. 22 , the method of the controller 110acquiring the detailed phase correction value may include an operationof the controller 110 acquiring a difference value among the lightinformation acquired for each of pixel information (S4220) and anoperation of the controller 110 correcting the phase of thereconstruction signal such that the acquired difference value among thelight information is minimized (S4240).

Here, referring to FIGS. 14 and 22 , the method of the controller 110acquiring the detailed phase correction value may be included in oridentical to the operation of the controller 110 acquiring the detailedphase correction value (S4200).

FIG. 23 is a schematic diagram showing a plurality of pieces of lightinformation acquired for one piece of pixel information according to anembodiment. The plurality of acquired pieces of light information mayinclude a first light information set and a second light informationset.

Here, the first light information set and the second light informationset may be pieces of light information acquired at different times.Also, each of the first light information set and the second lightinformation set may include at least one piece of light information.

For example, the first light information set may be a set of pieces oflight information corresponding to continuous time information, and thesecond light information set may be a set of pieces of light informationcorresponding to continuous time information a certain time after thecontinuous time information from which the first light information setis acquired.

As a specific example, when the first light information set and thesecond light information set each have three pieces of lightinformation, the light information corresponding to the first lightinformation set may be acquired at 1 microsecond, 1.1 microseconds, and1.2 microseconds, and the light information corresponding to the secondlight information may be acquired at 5 microseconds, 5.1 microseconds,and 5.2 microseconds. Here, the time information may be acquired inunits of 0.1 microseconds, and accordingly, the light information mayalso be acquired in units of 0.1 microseconds. However, the timeinformation for which the first light information set and the secondlight information set are acquired is not limited to the above example,and the time information may vary depending on a unit time at which thetime information is acquired, a time required to complete one patterngenerated according to a driving signal or a reconstruction signal, etc.

In other words, the time information for which the first lightinformation set is acquired and the time information for which thesecond light information set is acquired being different from each othermay mean that a pattern generated by a driving signal or areconstruction signal in the pixel information in which the first lightinformation set and the second light information set are acquired hasintersections.

Referring to FIGS. 22 and 23 , the operation of the controller 110acquiring the difference value among the light information acquired foreach of pixel information (S4220) may include the controller 110acquiring the difference value between the pieces of light informationcorresponding to coordinate information acquired for the each of thepixel information.

According to an embodiment, the pixel information may refer to positioninformation regarding a position where a single pixel is placed among atotal number of pixels, and a plurality of pieces of coordinateinformation may be included in the pixel information.

In other words, the plurality of pieces of coordinate information mayindicate one piece of pixel information.

For example, the first light information set may include a plurality ofpieces of light information corresponding to a plurality of pieces ofcoordinate information, and a position indicated by a plurality ofpieces of coordinate information constituting the first lightinformation set may indicate a position within one piece of pixelinformation. In other words, even though a plurality of pieces ofcoordinate information may indicate different positions in detail, onepiece of pixel information may include different positions indicated bythe plurality of pieces of coordinate information.

This may mean that a plurality of pieces of light information may beacquired in one piece of pixel information.

According to an embodiment, the difference value between the pieces oflight information may be meant to include the difference, the mean, thevariance, and the standard deviation of the pieces of the lightinformation.

For example, the difference between the sum of pieces of lightinformation constituting the first light information set and the sum ofpieces of light information constituting the second light informationset may refer to the difference value between the pieces of lightinformation.

As another example, the average of at least some of the pieces of lightinformation constituting the first light information set and the secondlight information set may refer to the difference value between thepieces of light information.

Also, as another example, the variance of the plurality of pieces oflight information from the average of at least some of the pieces oflight information constituting the first light information set and thesecond light information set may refer to the difference value betweenthe pieces of light information.

Also, as another example, the standard deviation of the plurality ofpieces of light information from the average of at least some of thepieces of light information constituting the first light information setand the second light information set may refer to the difference valuebetween the pieces of light information.

However, the present invention is not limited to the above example, andthe acquisition of the difference value between the pieces of lightinformation may mean that the plurality of pieces of light informationacquired for the pixel information are uniform. Here, the plurality ofpieces of light information being uniform may refer to whether theplurality of acquired pieces of light information have the same orsimilar light information.

Here, when there is no phase delay in the reconstruction signal, theplurality of pieces of light information acquired for the pixelinformation may all have the same value. That is, the difference valuebetween the pieces of light information may be equal or close to zero.

However, when there is a phase delay in the reconstruction signal, thedifference value between the pieces of light information acquired forthe pixel information may occur. That is, as the phase delay value ofthe reconstruction signal increases, the difference value between thepieces of light information acquired for the pixel information mayincrease.

Referring to FIG. 22 , the operation of the controller 110 correctingthe phase of the reconstruction signal such that the difference valuebetween among the light information is minimized (S4240) may include thecontroller 110 changing the phase of the reconstruction signal todetermine whether the difference value between the pieces of lightinformation acquired for the pixel information is minimized.

According to an embodiment, a user of the image generation device mayadjust the difference value between the pieces of light informationacquired by the controller 110 to be minimized while manually changingthe phase of the reconstruction signal.

According to another embodiment, the controller 110 may change the phaseof the reconstruction signal in a minimum unit capable of changing thephase of the reconstruction signal and thus may change the phase of thereconstruction signal such that the difference value between the piecesof light information acquired for the pixel information is minimized.

According to still another embodiment, the controller 110 mayarbitrarily change the phase of the reconstruction signal and thus maychange the phase of the reconstruction signal such that the differencevalue between the pieces of light information acquired for the pixelinformation is minimized.

According to still another embodiment, the controller 110 may change thephase of the reconstruction signal in predetermined phase adjustmentunits and thus may change the phase of the reconstruction signal suchthat the difference value between the pieces of light informationacquired for the pixel information is minimized.

In the aforementioned embodiments, the controller 110 may acquire thedifference value between the pieces of light information acquired forpixel information each time the phase is adjusted. However, the presentinvention is not limited thereto, and the controller 110 may acquire thedifference value between the pieces of light information acquired forthe pixel information on the basis of the phase value of the at leastone reconstruction signal.

FIG. 24 is a flowchart illustrating a method of the controller 110adjusting the phase of a reconstruction signal and comparing the minimumvalues of light information acquired for pixel information to acquire adetailed phase correction value according to an embodiment.

Referring to FIG. 24 , the method of the controller 110 adjusting thephase of a reconstruction signal and comparing the minimum values oflight information acquired for pixel information to acquire a detailedphase correction value may include an operation of the controller 110acquiring the difference among the light information acquired for eachof pixel information (S4220), an operation of the controller 110adjusting the phase of the reconstruction signal (S4242), an operationof the controller 110 acquiring the difference value between among thelight information acquired for the each of the pixel information afteradjusting the phase of the reconstruction signal (S4244), an operationof the controller 110 comparing the difference value among the lightinformation before the adjustment of the phase of the reconstructionsignal and the difference value among the light information after theadjustment of the phase of the reconstruction signal (S4246), and anoperation of the controller 110 correcting the phase of thereconstruction signal with the phase of the reconstruction signalcorresponding to when the difference value is acquired before the phaseof the reconstruction signal is adjusted (S4248).

Referring to FIG. 24 , the operation of the controller 110 acquiring thedifference value among the light information acquired for each of thepixel information (S4220) may be identical to the above operation of thecontroller 110 acquiring the difference value between the pieces oflight information acquired for each of the pixel information, which isshown in FIG. 22 .

Referring to FIG. 24 , the operation of the controller 110 adjusting thephase of the reconstruction signal (S4242) may include a method of thecontroller 110 adjusting the phase of the reconstruction signal on thebasis of the aforementioned embodiments.

According to an embodiment, when the controller 110 adjusts the phase ofthe reconstruction signal, the controller 110 may adjust the phase ofthe reconstruction signal on the basis of the predetermined phaseadjustment unit.

The predetermined phase adjustment unit in which the controller 110adjusts the phase of the reconstruction signal will be described indetail in the following related section.

According to another embodiment, when the controller 110 adjusts thephase of the reconstruction signal, the controller 110 may arbitrarilyadjust the phase of the reconstruction signal.

According to another embodiment, when the controller 110 adjusts thephase of the reconstruction signal, the controller 110 may adjust thephase of the reconstruction signal on the basis of the minimum phaseunit capable of adjusting the phase of the reconstruction signal.

Referring to FIG. 24 , the operation of the controller 110 acquiring thedifference value among the light information acquired for each of thepixel information after adjusting the phase of the reconstruction signal(S4244) may include the above method of the controller 110 acquiring thedifference value between the pieces of light information for the pixelinformation during the operation of the controller 110 acquiring thedifference value among the light information acquired for each of thepixel information (S4220).

Here, when the controller 110 adjusts the phase of the reconstructionsignal, the light information acquired for the pixel information may bedifferent from the light information before the controller 110 adjuststhe phase of the reconstruction signal. In other words, when thecontroller 110 adjusts the phase of the reconstruction signal,coordinate information acquired based on the reconstruction signal maybe different from coordinate information before the controller 110adjusts the phase of the reconstruction signal. Accordingly, lightinformation corresponding to the coordinate information included in thepixel information may vary before and after the controller 110 adjuststhe phase of the reconstruction signal.

Referring to FIG. 24 , the operation of the controller 110 comparing thedifference value between the pieces of light information before theadjustment of the phase of the reconstruction signal and the differencevalue between the pieces of light information after the adjustment ofthe phase of the reconstruction signal (S4246) includes the controller110 acquiring difference values between the pieces of light informationfor the pixel information before and after adjusting the phase of thereconstruction signal and comparing the difference value between thepieces of light information for the pixel information before theadjustment of the phase of the reconstruction signal and the differencevalue between the pieces of light information for the pixel informationafter the adjustment of the phase of the reconstruction signal.

In this case, the controller 110 comparing the difference value betweenthe pieces of light information for the pixel information before theadjustment of the phase of the reconstruction signal and the differencevalue between the pieces of light information for the pixel informationafter the adjustment of the phase of the reconstruction signal may meanthat the controller 110 compares the difference value between the piecesof light information acquired immediately before the adjustment of thephase of the reconstruction signal and the difference value between thepieces of light information acquired immediately after the adjustment ofthe phase of the reconstruction signal.

When the operation of the controller 110 adjusting the phase of thereconstruction signal is performed more than one time, the controller110 comparing the difference values may mean that the controller 110compares the difference value between the pieces of light informationacquired for pixel information after the second to last phase correctionis performed and before the last phase correction is performed and thedifference value between the pieces of light information acquired forthe pixel information after the last phase correction is performed.

For convenience of the following description, the difference valuebetween the pieces of light information acquired for the pixelinformation before the controller 110 adjusts the phase of thereconstruction signal may be expressed as a difference value betweenpieces of light information before phase adjustment, and the differencevalue between the pieces of light information acquired for the pixelinformation after the controller 110 adjusts the phase of thereconstruction signal may be expressed as a difference value betweenpieces of light information after phase adjustment.

Here, when the difference value between the pieces of light informationbefore phase adjustment is larger than the difference value between thepieces of light information after phase adjustment, the controller 110may re-adjust the phase of the reconstruction signal. In other words,when the difference value between the pieces of light information beforephase adjustment is greater than the difference value between the piecesof light information after phase adjustment, the operation of thecontroller 110 adjusting the phase of the reconstruction signal (S4242)may be performed again.

Here, when the difference value between the pieces of light informationbefore phase adjustment is smaller than the difference value between thepieces of light information after phase adjustment, the controller 110may reconstruct the phase of the reconstruction signal on the basis of aphase adjusted before the controller 110 performs the last phaseadjustment on the reconstruction signal. In other words, when thedifference value between the pieces of light information before phaseadjustment is smaller than the difference value between the pieces oflight information after phase adjustment, the operation of thecontroller 110 correcting the phase of the reconstruction signal with aphase value of the reconstruction signal upon the acquirement of thedifference value before the adjustment of the phase of thereconstruction signal may be performed (S4248).

Referring to FIG. 24 , the operation of the controller 110 correctingthe phase of the reconstruction signal with the phase value of thereconstruction signal upon the acquirement of the difference valuebefore the adjustment of the phase of the reconstruction signal (S4248)may include the controller 110 correcting the phase of thereconstruction signal on the basis of the phase of the reconstructionsignal adjusted immediately before the phase of the reconstructionsignal is finally adjusted.

Here, the phase of the reconstruction signal adjusted immediately beforethe phase of the reconstruction signal is finally adjusted may refer toa phase value of the reconstruction signal which is a basis for theacquirement of the difference value between the pieces of lightinformation before the phase adjustment. In other words, when theoperation of the controller 110 adjusting the phase of thereconstruction signal is included before the operation of the controller110 correcting the phase of the reconstruction signal with the phasevalue of the reconstruction signal upon the acquirement of thedifference value before the adjustment of the phase of thereconstruction signal (S4248), the phase of the reconstruction signaladjusted immediately before the controller 110 finally adjusts the phaseof the reconstruction signal may be acquired based on the phase of thereconstruction signal corresponding to before the phase of thereconstruction signal is finally adjusted.

Here, the correction of the phase of the reconstruction signal mayinclude the controller 110 acquiring coordinate information on the basisof the phase correction value of the reconstruction signal as describedabove.

In this case, the phase value used by the controller 110 to correct thephase of the reconstruction signal may be the detailed phase correctionvalue.

FIG. 25 is a flowchart illustrating a method of the controller 110additionally adjusting the phase of the reconstruction signal andacquiring a detailed phase correction value according to an embodiment.

Referring to FIG. 25 , the method of the controller 110 additionallyadjusting the phase of a reconstruction signal and acquiring a detailedphase correction value may include an operation of the controller 110adjusting the phase of the reconstruction signal (S5000), an operationof the controller 110 acquiring a difference value among the lightinformation acquired for each of the pixel information after adjustingthe phase of the reconstruction signal (S5200), and an operation of thecontroller 110 comparing the difference value among the lightinformation before the adjustment of the phase of the reconstructionsignal and the difference value among the light information after theadjustment of the phase of the reconstruction signal (S5400).

According to an embodiment, the controller 110 may acquire the phase ofthe reconstruction signal corresponding to the minimized differencevalue of the light information after adjusting the phase of thereconstruction signal in predetermined phase adjustment units, adjustthe phase of the reconstruction signal in units smaller than thepredetermined phase adjustment units to acquire the minimized differencevalue of the light information, and acquire a phase correction value ofthe reconstruction signal corresponding to the minimized differencevalue of the light information.

For example, referring to FIGS. 24 and 25 , the method of the controller110 additionally adjusting the phase of the reconstruction signal andacquiring the detailed phase correction value may be performed by thecontroller 110 between the operation of the controller 110 comparing thedifference value between the pieces of light information before theadjustment of the phase of the reconstruction signal and the differencevalue between the pieces of light information after the adjustment ofthe phase of the reconstruction signal and the operation of thecontroller 110 correcting the phase of the reconstruction signal with aphase value of the reconstruction signal upon the acquirement of thedifference value before the adjustment of the phase of thereconstruction signal, which are shown in FIG. 24 .

Referring to FIG. 25 , the operation of the controller 110 adjusting thephase of the reconstruction signal (S5000) may include the controller110 adjusting the phase of the reconstruction signal on the basis of aphase adjustment unit smaller than the predetermined phase adjustmentunit.

For example, when the controller 110 adjusts the phase of thereconstruction signal by a first phase adjustment unit in the operationof the controller 110 adjusting the phase of the reconstruction signal(S4242), the controller 110 may adjust the phase of the reconstructionsignal on the basis of a second phase adjustment unit smaller than thefirst phase adjustment unit in the operation of the controller 110adjusting the phase of the reconstruction signal (S5000).

As a specific example, when the first phase adjustment unit is 0.1seconds, the second phase adjustment unit may be set to 0.05 seconds,which is smaller than the first phase adjustment unit. The controller110 may adjust the phase of the reconstruction signal on the basis ofthe first phase adjustment unit to acquire the phase of thereconstruction signal such that the difference value between the piecesof light information for the pixel information is minimized, and thenthe controller 110 may adjust the phase of the reconstruction signal onthe basis of the second phase adjustment unit to acquire the phase ofthe reconstruction signal such that the difference value between thepieces of light information for the pixel information is minimized.

Referring to FIGS. 24 and 25 , the operation of the controller 110acquiring a difference value among the light information acquired foreach of the pixel information after adjusting the phase of thereconstruction signal (S5200) and the operation of the controller 110comparing the difference value among the light information before theadjustment of the phase of the reconstruction signal and the differencevalue among the light information after the adjustment of the phase ofthe reconstruction signal (S5400) may be the same as or similar to theoperation of the controller 110 acquiring a difference value among thelight information for each of the pixel information after adjusting thephase of the reconstruction signal (S4244) and the operation of thecontroller 110 comparing the difference value between the pieces oflight information before the adjustment of the phase of thereconstruction signal and the difference value between the pieces oflight information after the adjustment of the phase of thereconstruction signal (S4246).

In other words, the operation of the controller 110 acquiring adifference value among the light information acquired for pixelinformation after adjusting the phase of the reconstruction signal(S5200) and the operation of the controller 110 comparing the differencevalue among the light information before the adjustment of the phase ofthe reconstruction signal and the difference value among lightinformation after the adjustment of the phase of the reconstructionsignal (S5400) may be performed by the controller 110 in the same manneras the method used in the aforementioned operations.

3.3.2. Predetermined Phase Adjustment Unit

The predetermined phase adjustment unit, which is a unit in which thecontroller 110 adjusts the phase of the reconstruction signal will bedescribed below.

Here, the predetermined phase adjustment unit may be expressed as a dip.

FIG. 26 includes diagrams showing that the form of a generated patternis repeated along with a change in the phase of a driving signal or areconstruction signal according to an embodiment.

Specifically, (a) and (c) of FIG. 26 show the same form of patterns, butthe patterns may have phases of a driving signal or a reconstructionsignal different from each other on the basis of the predetermined phaseadjustment unit. (b) of FIG. 26 shows the form of a pattern differentfrom that of (a) of FIG. 26 or (c) of FIG. 26 and may be a pattern witha phase different from the phase of the driving signal or thereconstruction signal, which is a basis shown in (a) of FIG. 26 or (c)of FIG. 26 , by half of the predetermined phase adjustment unit.

According to an embodiment, the form of the pattern of the drivingsignal or the reconstruction signal may be repeated each time the phaseof the first-axis signal or the second-axis signal of the driving signalor the reconstruction signal is adjusted or changed by the predeterminedphase adjustment unit. In other words, when the pattern of the drivingsignal or the reconstruction signal is repeated, the phase of thefirst-axis signal or the second-axis signal of the driving signal or thereconstruction signal may differ on the basis of the predetermined phaseadjustment unit.

For example, referring to FIG. 26 , when the phase of the driving signalor the reconstruction signal is adjusted based on the driving signal orthe reconstruction signal which is a basis shown in (a) of FIG. 26 , theform of the pattern may exhibit the pattern of (b) of FIG. 26 and thenthe pattern of (c) of FIG. 26 . Here, the pattern of (a) of FIG. 26 andthe pattern of (c) of FIG. 26 may have the same form. In this case, thephase of the driving signal or the reconstruction signal which is abasis shown in (a) of FIG. 26 may differ from the phase of the drivingsignal or the reconstruction signal which is a basis shown in (c) ofFIG. 26 by a dip, which is the predetermined phase adjustment unit.

FIG. 27 is a diagram showing that an FF is repeated according to thephases of a first-axis signal and a second-axis signal of a drivingsignal or a reconstruction signal according to an embodiment.

In FIG. 27 , the x-axis represents the phase of the first-axis signal ofthe driving signal or the reconstruction signal, and the y-axisrepresents the phase of the second-axis signal of the driving signal orthe reconstruction signal.

Also, in FIG. 27 , the same color may mean that patterns exhibited dueto the driving signal or the reconstruction signal have the same orsimilar FFs. Here, the color shown in FIG. 27 may have an increasing FFas the brightness increases, that is, as the color changes from black towhite.

In this case, referring to FIG. 27 , the color shown in FIG. 27 mayrefer to a difference value among the light information acquired foreach of pixel information of an image in addition to the FF.

According to an embodiment, the FF of the driving signal or thereconstruction signal may be repeated each time the phase of the drivingsignal or the reconstruction signal is adjusted or changed by thepredetermined phase adjustment unit. In other words, the driving signalor the reconstruction signal may have the same FF each time thefirst-axis signal or the second-axis signal of the driving signal or thereconstruction signal changes by a dip.

Specifically, referring to FIG. 27 , the FF may change repeatedly as thephase of the first-axis signal or the second-axis signal of the drivingsignal or the reconstruction signal changes. In this case, an intervalof the phase of the first signal or the second signal in which the FF isrepeated may be a dip, which is the predetermined phase adjustment unit.

$\begin{matrix}{{dip} = \frac{GCD}{2f_{x}f_{y}}} & \lbrack {{Equation}\mspace{14mu} 3} \rbrack\end{matrix}$

Referring to Equation 3, dip indicates the predetermined phaseadjustment unit, GCD indicates the greatest common divisor of thefirst-axis frequency and the second-axis frequency of the driving signalor the reconstruction signal, f_(x) indicates the first-axis frequencyof the driving signal or the reconstruction signal, and f_(y) indicatesthe second-axis frequency of the driving signal or the reconstructionsignal.

According to an embodiment, the controller 110 may acquire thepredetermined phase adjustment unit for adjusting the phase of thereconstruction signal on the basis of the first-axis frequency and thesecond-axis frequency of the reconstruction signal. In other words, thecontroller 110 may acquire the predetermined phase adjustment unit foradjusting the phase of the reconstruction signal on the basis of thefirst-axis frequency and the second-axis frequency of the reconstructionsignal.

According to another embodiment, the controller 110 may acquire thepredetermined phase adjustment unit for adjusting the phase of thereconstruction signal on the basis of the first-axis co-prime frequencyand the second-axis co-prime frequency of the reconstruction signal. Inother words, the controller 110 may acquire the predetermined phaseadjustment unit for adjusting the phase of the reconstruction signal onthe basis of the first-axis co-prime frequency and the second-axisco-prime frequency of the reconstruction signal.

3.3.3. BPSA

An example in which the controller 110 adjusts the phase of thereconstruction signal using a BPSA method will be described below.

Here, “BPSA” is an abbreviation of “Boundary Phase Search Algorithm,”and may refer to a method of the controller 110 acquiring a detailedphase correction value of the reconstruction signal using only somepixel information, and in particular, a method of controller 110acquiring a detailed phase correction value of the reconstruction signalusing light information corresponding to pixel information for pixels inclose proximity to a boundary of an image.

In this case, the proximity of the boundary of the image may refer to asmany regions as the predetermined number of pixels in a direction fromends of which are located on the top, bottom, left, and right of animage acquired by the controller 110 and from which pixel information isacquired toward the center of the image. In other words, the proximityof the boundary of the image may be an edge in the entire pixel regionof the acquired image. Here, the predetermined number of pixels is anarbitrarily set value and may be changed in consideration of the amountof computation of the controller 110.

That is, when using the BPSA method, the controller 110 may compute theminimum value of the light information using light information orcoordinate information acquired from some pixel information other thanall of the pixel information, and thus it is possible to reduce the timerequired for the controller 110 to correct the phase of thereconstruction signal. In other words, when the controller 110 uses theBPSA method, it is possible to reduce the amount of computation of thecontroller 110. That is, it is possible to increase the speed at whichthe controller 110 corrects the phase of the reconstruction signal.

Here, the acquisition of the coordinate information for the pixelinformation may mean that a position indicated by the coordinateinformation in all the pixels is included in a position indicated byspecific pixel information. Likewise, the acquisition of lightinformation may mean that the position indicated by coordinateinformation corresponding to light information in all the pixels isincluded in the position indicated by the specific pixel information.Hereinafter, for convenience of description, the position indicated bythe coordinate information or the position indicated by the coordinateinformation corresponding to the light information being included in theposition indicated by the pixel information is expressed as thecoordinate information or the light information being acquired.

FIG. 28 is a diagram showing the density of light information acquiredfor pixel information in the entire pixel range according to anembodiment.

Referring to FIG. 28 , bar graphs on the horizontal axis and thevertical axis are graphs showing the number of pieces of or the densityof light information or coordinate information acquired forcorresponding pixel information. Specifically, the bar graph shown onthe horizontal axis or the vertical axis may indicate the number ofpieces of or the density of coordinate information or light informationincluded for pixel information acquired on the entire axis.

Referring to FIG. 28 , in the entire pixel range of the acquired image,more coordinate information or light information may be acquired forpixel information having darker color than for pixel information havingbrighter color. In other words, the coordinate information or lightinformation acquired for darker pixel information may have a higherdensity than the coordinate information or light information acquiredfor brighter pixel information.

Here, referring to FIG. 28 , the darker color may mean that the colorbecomes darker from white to black.

FIG. 29 includes diagrams showing light information or coordinateinformation acquired for pixel information of a partial region of anacquired image according to an embodiment.

As a specific example, referring to FIG. 29 , (a) of FIG. 29 is adiagram showing coordinate information or light information acquired inclose proximity to a central region in which the number of pieces of orthe density of coordinate information or light information is small inthe entire pixel region, and (b) of FIG. 29 is a diagram showingcoordinate information or light information acquired in close proximityto a boundary region in which the number of pieces of or the density ofcoordinate information or light information is great in the entire pixelregion.

Referring to FIG. 29 , the number of pieces of or the density ofcoordinate information or light information acquired in a specific pixelregion may be greater than those in the other pixel regions.

For example, when the driving signal or the reconstruction signalexhibits a Lissajous pattern, in the entire pixel region, the number ofpieces of or the density of coordinate information or light informationincluded in a pixel region including pixel information may be greater inthe edge region than in the central region.

Here, for example, the number of pieces of coordinate information orlight information acquired in an edge pixel region may be at least 50%or more of the total number of pieces of acquired coordinate informationor light information.

FIG. 30 is a flowchart illustrating a method of correcting a phase onthe basis of light information or coordinate information acquired insome pixel regions according to an embodiment.

Referring to FIG. 30 , the method of correcting a phase on the basis oflight information or coordinate information acquired for some pixelregions may include an operation of the controller 110 acquiring adifference value between pieces of light information acquired for someof the whole pixel information (S6000) and an operation of thecontroller 110 correcting a phase such that the difference value amongthe light information is minimized (S6200).

Here, the method of correcting the phase on the basis of lightinformation or coordinate information acquired in some pixel regions maybe included in the above operation of the controller 110 acquiring thedetailed phase correction value (S4200).

Referring to FIG. 30 , the operation of the controller 110 acquiring thedifference value between the pieces of light information acquired forsome of the whole pixel information (S6000) may include the controller110 acquiring the difference value not using the whole light informationcorresponding to the whole acquired coordinate information but usinglight information corresponding to some of the acquired coordinateinformation.

According to an embodiment, the controller 110 may acquire thedifference value using light information or coordinate informationacquired in an edge pixel region. Here, the edge pixel region may referto pixel information for pixels in close proximity to a boundary of animage, as described above.

Specifically, the coordinate information acquired in the edge pixelregion may refer to coordinate information acquired for at least onelayer of pixel information in an edge of the entire acquired pixelregion.

Here, one layer of pixel information may refer to all of the pixelinformation located in a direction of the selected one of the first axisand the second axis. For example, when there are 256 pieces of pixelinformation in the first axis, one layer of pixel information may referto 256 pieces of pixel information.

According to another embodiment, the controller 110 may acquire thedifference value using at least one piece of light informationcorresponding to coordinate information acquired for the edge pixelregion. In other words, when there is light information corresponding toone piece of pixel information in the edge pixel region, the controller110 may acquire the difference value using a portion, but not all, ofthe corresponding light information.

The controller 110 acquiring the difference value using at least onepiece of light information corresponding to coordinate information willbe described below in the following related section.

Referring to FIG. 30 , the operation of the controller 110 correctingthe phase such that the difference value among the light information isminimized (S6200) may be the same as or included in the operation of thecontroller 110 correcting the phase of the reconstruction signal suchthat the difference value between among the light information isminimized (S4240).

According to an embodiment, by using light information or coordinateinformation acquired for some of all of the pixel information, thecontroller 110 may acquire the difference value between the pieces oflight information.

Accordingly, in order to minimize the difference value between thepieces of light information, the controller 110 may change the phase ofthe reconstruction signal and determine whether the difference valuebetween the pieces of light information acquired for the pixelinformation is minimized as in the above operation of the controller 110correcting the phase of the reconstruction signal such that thedifference value between among the light information is minimized(S4240).

3.3.4. GPSA

An example in which the controller 110 adjusts the phase of thereconstruction signal using a GPSA method will be described below.

Here, “GPSA” is an abbreviation of “Global Phase Search Algorithm” andmay refer to a method of the controller 110 acquiring a detailed phasecorrection value of the reconstruction signal using at least one pieceof light information corresponding to coordinate information acquiredfor some pixel information. In particular, the coordinate informationcorresponding to the used light information may be light informationindicating the same or a similar position.

When the controller 110 uses the GPSA method, similar to the controller110 using the BPSA method, some of all of the light information acquiredfor all of the pixel information is used. Thus, it is possible to reducethe amount of computation of the controller 110, and accordingly, it ispossible to increase the speed at which the controller 110 corrects thephase of the reconstruction signal.

FIG. 31 includes schematic diagrams showing an intersection of a patternexhibited according to a driving signal or a reconstruction signalaccording to an embodiment.

As a specific example, referring to FIG. 31 , (a) of FIG. 31 is adiagram showing intersections of a pattern exhibited according to adriving signal or a reconstruction signal in an intersection pixelregion, and (b) of FIG. 31 is a diagram showing firstintersection-related light information and second intersection-relatedlight information acquired for coordinate information in whichintersections of the pattern in the intersection pixel region areidentical or similar.

According to an embodiment, the difference value between the pieces oflight information acquired by the controller 110 may be a differencevalue between pieces of light information acquired for coordinateinformation in which intersections of the pattern exhibited by thedriving signal or the reconstruction signal are identical or similar.

Here, an intersection of the pattern may mean that the pattern forms anintersection when the same coordinate information corresponding todifferent time points is present, and a crossing of the pattern or anedge of a region where the pattern is generated may also refer to anintersection of the pattern.

For example, referring to FIGS. 5, 6, and 31 above, the difference valuebetween the pieces of light information acquired by the controller 110may be a difference value between first intersection-related lightinformation and second intersection-related light information.

Here, time information acquired to correspond to the firstintersection-related light information may be different from timeinformation acquired to correspond to the second intersection-relatedlight information, but coordinate information corresponding to the firstintersection-related light information may be identical to or similar tocoordinate information corresponding to the second intersection-relatedlight information.

As a specific example, referring to FIGS. 5 and 6 above, i1, which isacquired according to t1, may be the first intersection-related lightinformation, and t2, which is acquired according to t2, may be thesecond intersection-related light information. Here, the coordinateinformation corresponding to t1 may be x1 and y1, and the coordinateinformation corresponding to t2 may be x2 and y2. In this case, theposition of the coordinate information indicated by x1 and y1 may beidentical to or similar to the position of the coordinate informationindicated by x2 and y2. That is, the time information acquired tocorrespond to i1 may be different from the time information acquired tocorrespond to i2, but the position represented by the coordinateinformation corresponding to i1 may be identical to or similar to theposition represented by the coordinate information corresponding to i2.

According to an embodiment, the controller 110 may correct the phase ofthe reconstruction signal using only light information corresponding tocoordinate information of an intersection of the pattern exhibited bythe driving signal or the reconstruction signal.

A method of the controller 110 correcting the phase of thereconstruction signal using only the light information corresponding tothe coordinate information of the intersection of the pattern exhibitedby the driving signal or the reconstruction signal will be describedbelow.

For convenience of the following description, when positions indicatedby pieces of coordinate information are identical or similar to eachother, the pieces of coordinate information may be expressed as beingidentical to or similar to each other. Also, the controller 110acquiring coordinate information may mean that the controller 110 alsoacquires a position indicated by the coordinate information.

FIG. 32 is a flowchart illustrating a method of the controller 110correcting the phase of the reconstruction signal by using lightinformation acquired for coordinate information of an intersection ofthe pattern exhibited by the driving signal or the reconstruction signalaccording to an embodiment.

Referring to FIG. 32 , the method of the controller 110 correcting thephase of the reconstruction signal using the light information acquiredfor the coordinate information of the intersection of the patternexhibited by the driving signal or the reconstruction signal may includean operation of the controller 110 acquiring an offset for thecoordinate information of the intersection of the pattern on the basisof the reconstruction signal before correcting the phase (S7000), anoperation of the controller 110 acquiring a first phase correction valueand a minimum offset from the acquired offset such that a differenceamong the light information acquired for the coordinate information isminimized (S7200), an operation of the controller 110 changing the phaseof the reconstruction signal and acquiring a second phase correctionvalue at which the difference between the pieces of the lightinformation is minimized on the basis of coordinate information of theminimum offset (S7400), and an operation of the controller 110correcting the phase of the reconstruction signal on the basis of thefirst phase correction value and the second phase correction value(S7600).

Here, the method of the controller 110 correcting the phase of thereconstruction signal using light information acquired to correspond tocoordinate information of an intersection of the pattern exhibited bythe driving signal or the reconstruction signal may be included in theabove operation of the controller 110 acquiring the detailed phasecorrection value (S4200).x=A _(x) sin(2πf _(x)(t _(d))), y=A _(y) sin(2πf _(x)(t _(d)+c))  [Equation 4]

Equation 4 is an equation representing a reconstruction signal that canbe used to convert time information into coordinate information and adriving signal that is for determining a pattern in which light isemitted to an object according to an embodiment.

Equation 4 is an equation representing the initial time of Equation 1above, that is, t=0. Here, φ_(x) may be acquired based on a firstfrequency and t_(d). More specifically, t_(d) may represent the phase ofa first-axis driving signal or a first-axis reconstruction signal whichis a driving signal or a reconstruction signal when t=0. Also, here, cmay be an element for determining the shape of the pattern. Here, φ_(y)may be acquired based on a second frequency and t_(d)+c. That is, thephase of the first-axis driving signal or the first-axis reconstructionsignal may be different from the phase of a second-axis driving signalor a second-axis reconstruction signal by c. Also, a start point of thepattern exhibited by the driving signal or the reconstruction signal maybe determined by t_(d) and c. In other words, the start point of thepattern may be coordinate information that is represented based onEquation 4 when t=0.

In this case, t_(d) and φ_(x) may refer to the phase of the first-axisdriving signal or the first-axis reconstruction signal, and t_(d)+c andφ_(y) may refer to the phase of the second-axis driving signal or thesecond-axis reconstruction signal. That is, t_(d) and t_(d)+c may referto the phase of a driving signal or a reconstruction signal that issubstantially proportional to φ_(x) and φ_(y) when the first frequencyand the second frequency are fixed.

Referring to FIGS. 32 and 7 , the operation of the controller 110acquiring an offset for coordinate information of an intersection of thepattern on the basis of the reconstruction signal before the phasecorrection (S7000) may include an operation of the controller 110acquiring coordinate information or time information identical to orsimilar to the coordinate information on the basis of the reconstructionsignal before the correction of the phase. Here, the offset may refer toa plurality of pieces of coordinate information corresponding to aplurality of intersections of the pattern exhibited by the drivingsignal or the reconstruction signal. Alternatively, the offset may referto at least one piece of time information corresponding to at least oneintersection of the pattern exhibited by the driving signal or thereconstruction signal.

According to an embodiment, the controller 110 acquiring an offset forcoordinate information of the intersection of the pattern may mean thatwhen there are a plurality of intersections of the pattern exhibited bythe driving signal or the reconstruction signal, the controller 110acquires a plurality of pieces of coordinate information correspondingto the plurality of intersections.

For example, referring to FIGS. 5 and 6 above, the controller 110 mayacquire i1 to i4, which are pieces of light information, correspondingto t1 to t4, which are pieces of time information. Here, t1 to t4, whichare pieces of time information, may correspond to x1 to x4, which arepieces of first-axis coordinate information of the driving signal or thereconstruction signal, and may correspond to y1 to y4, which are piecesof second-axis coordinate information of the driving signal or thereconstruction signal. That is, i1 to i4, which are pieces of lightinformation acquired by the controller 110, may correspond to x1 to x4,which are pieces of first-axis coordinate information of the drivingsignal or the reconstruction signal, respectively, and may correspond toy1 to y4, which are pieces of second-axis coordinate information of thedriving signal or the reconstruction signal, respectively.

Here, for example, the position indicated by x1 and y1, which are piecesof coordinate information corresponding to the time information t1, maybe identical to or similar to the position indicated by x3 and y3, whichare pieces of coordinate information corresponding to the timeinformation t3. Likewise, the position indicated by x2 and y2, which arepieces of coordinate information corresponding to the time informationt2, may be identical to or similar to the position indicated by x4 andy4, which are pieces of coordinate information corresponding to the timeinformation t4.

In this case, offsets acquired by the controller 110 may be (t1, t3) and(t2, t4) on the basis of the time information. Alternatively, offsetsacquired by the controller 110 may be (x1, y1), (x3, y3), (x2, y2), and(x4, y4) on the basis of the coordinate information. In other words, inthe case of the offsets acquired by the controller 110, when pieces ofcoordinate information indicated by at least two pieces of timeinformation are identical to or similar to each other, the two pieces oftime information may constitute one offset. The offsets may be aplurality of offsets configured based on time information correspondingto a plurality of intersections of the pattern. Also, in the case of theoffsets acquired by the controller 110, at least two pieces ofcoordinate information of the intersections of the pattern mayconstitute one offset, and at least two pieces of coordinate informationfor a plurality of intersections of the pattern may be a plurality ofacquired offsets.

For convenience of the following description, the controller 110acquiring at least one offset will be described as the controller 110acquiring an offset.

Also, according to an embodiment, the controller 110 may acquire anoffset on the basis of a reconstruction signal before phase correction.Here, the reconstruction signal before the phase correction may meanthat there are no phase-related elements in the reconstruction signal.

For example, referring to Equations 1 and 4 above, the reconstructionsignal from which the controller 110 acquires the offset may be a signalwith t_(d) and c of zero. In other words, the reconstruction signal fromwhich the controller 110 acquires the offset may be a signal with φ_(x)and φ_(y) of zero.

That is, the controller 110 may change the time information and mayacquire coordinate information of an intersection of the patternindicated by the reconstruction signal or time information correspondingto the coordinate information of the intersection of the patternindicated by the reconstruction signal.

As a result, the controller 110 may acquire an offset on the basis of areconstruction signal with a phase of zero.

FIG. 33 includes schematic diagrams showing intersections acquired fromdifferent patterns according to an embodiment.

Specifically, referring to Equation 1, Equation 4, and FIG. 33 above,(a) of FIG. 33 and (b) of FIG. 33 show patterns exhibited by the samedriving signal or reconstruction signal except for c, which is anelement for determining a pattern shape. In other words, (a) and (b) ofFIG. 33 may show patterns that are exhibited by a first-axis signal anda second-axis signal which have the same frequency and amplitude andthat have different values of c when the phase of the first-axis signalis different from the phase of the second-axis signal by c.

According to an embodiment, even if the phase difference between thefirst-axis signal and the second-axis signal of the driving signal orthe reconstruction signal exhibiting the pattern is changed,intersections may be reached at the same time interval in a direction inwhich the pattern proceeds.

For example, referring to Equation 1, Equation 4, and FIG. 33 above, atime interval between time information corresponding to coordinateinformation of a first intersection and time information correspondingto coordinate information of a second intersection when the patternproceeds from the first intersection to the second intersection as shownin (a) of FIG. 33 may be identical to a time interval between timeinformation corresponding to coordinate information of a thirdintersection and time information corresponding to coordinateinformation of a fourth intersection when the pattern proceeds from thethird intersection to the fourth intersection as shown in (b) of FIG. 33.

That is, pieces of time information corresponding to offsets acquiredfrom driving signals or reconstruction signals exhibiting two patternswith different phase differences between the first-axis signal and thesecond-axis signal may be different from each other by the same timeinterval. In other words, even if the phases of the first-axis signaland the second-axis signal of the driving signal and the reconstructionsignal are different from each other, the pieces of time informationwhich correspond to the acquired offsets may have the same time intervalas time information from which the offsets are acquired.

Referring to FIGS. 32 and 33 , the operation of the controller 110acquiring a first phase correction value and a minimum offset such thata difference among the light information acquired for coordinateinformation in the acquired offset is minimized (S7200) may include thecontroller 110 changing time information corresponding to the acquiredoffset to several time intervals, acquiring time information such that adifference value between pieces of light information in the offsets isminimized, and acquiring a minimum offset corresponding to the timeinformation.

Here, referring to Equation 1 and Equation 4 above, the controller 110changing the time information of the offset may mean that the controller110 changes t_(d) of the driving signal or the reconstruction signal andacquires a changed offset.

Also, referring to Equation 1 and Equation 4 above, the first phasecorrection value at which the difference between the pieces of lightinformation is minimized may be t_(d) at which the difference betweenthe pieces of light information of the coordinate informationcorresponding to the changed offset is minimized when the controller 110changes t_(d). In this case, when t_(d) of the driving signal or thereconstruction signal is the first phase correction value, the offsetacquired by the controller 110 may be the minimum offset.

According to an embodiment, the controller 110 may change t_(d) of thereconstruction signal and acquire the first phase correction value andthe minimum offset.

According to another embodiment, the controller 110 may acquire a firstphase correction value at which the difference between the pieces oflight information is minimized and a minimum offset corresponding to thefirst phase correction value among a plurality of offsets that changet_(d) of the reconstruction signal to a plurality of values.

In this case, in the above embodiments, a unit in which the controller110 changes t_(d) or an interval which is between a plurality of t_(d)'sacquired by the controller 110 may be predetermined. That is, thecontroller 110 may change t_(d) at predetermined intervals, acquire afirst phase correction value such that a difference between pieces oflight information is minimized, and acquire a minimum offsetcorresponding to the first phase correction value, and the controller110 may also acquire a plurality of t_(d)'s at predetermined timeintervals, acquire t_(d) in which the difference between the pieces oflight information is minimized among a plurality of correspondingoffsets, and acquire a minimum offset corresponding the first phasecorrection value.

Here, the interval between the plurality of t_(d)'s acquired by thecontroller 110 may refer to a difference between t_(d)'s which arecontinuously changed. For example, when t_(d1), t_(d2), and t_(d3)included in the plurality of t_(d)'s are continuous, the intervalbetween the plurality of t_(d)'s may refer to a difference betweent_(d1) and t_(d2).

Here, the plurality of offsets may be acquired by the controller 110 inthe form of a lookup table (LUT). That is, when the controller 110outputs a plurality of offsets, time information or coordinateinformation corresponding to the plurality of offsets may be output allat once.

Here, for example, a unit in which the controller 110 changes t_(d) or apredetermined interval which is between a plurality of t_(d)'s acquiredby the controller 110 may be a dip. However, the present invention isnot limited thereto, and the unit in which the controller 110 changest_(d) or the predetermined interval which is between a plurality oft_(d)'s acquired by the controller 110 may be a minimum unit in whichthe controller 110 can change the phase. Here, the minimum unit in whichthe controller 110 can change the phase may be a unit in whichcoordinate information acquired based on the driving signal or thereconstruction signal is substantially changed.

Referring to FIG. 32 , the operation of the controller 110 changing thephase of the reconstruction signal and acquiring a second phasecorrection value at which a difference between pieces of lightinformation is minimized on the basis of coordinate information of aminimum offset (S7400) may include the controller 110 changing the phasedifference between a first-axis signal and a second-axis signal of thereconstruction signal and acquiring a phase difference in which thedifference between the pieces of light information is minimized incoordinate information corresponding to the acquired minimum offset.

Here, referring to Equation 1 and Equation 4 above, the phase differencebetween the first-axis signal and the second-axis signal of thereconstruction signal may be c.

In this case, referring to FIG. 33 above, when the phase differencebetween the first-axis signal and the second-axis signal of thereconstruction signal varies, the shape of the pattern exhibited by thereconstruction signal may also vary. Accordingly, the difference betweenthe pieces of light information in the coordinate informationcorresponding to the acquired minimum offset may vary along with achange in the phase difference between the first-axis signal and thesecond-axis signal of the reconstruction signal.

In other words, when the controller 110 changes the phase differencebetween the first-axis signal and the second-axis signal of thereconstruction signal, the controller 110 may acquire a phase differencevalue at which a difference between the pieces of light information intime information corresponding to a minimize offset and coordinateinformation acquired based on the corresponding reconstruction signal isminimized. That is, the second phase correction value may refer to aphase difference value at which the difference between the pieces oflight information in the time information corresponding to the minimumoffset and the coordinate information acquired based on thecorresponding reconstruction signal is minimized. Also, here, the secondphase correction value may refer to c, which is a value at which thedifference between the pieces of light information in the timeinformation corresponding to the minimum offset and the coordinateinformation acquired based on the corresponding reconstruction signal isminimized.

According to an embodiment, the controller 110 may change c of thereconstruction signal and acquire the second phase correction value.

According to another embodiment, the controller 110 may acquire thesecond phase correction value at which the difference between the piecesof light information is minimized on the basis of a plurality of piecesof coordinate information acquired based on time informationcorresponding to the minimum offset and reconstruction signals obtainedby changing c of the reconstruction signal to a plurality of values.

In this case, in the above embodiments, a unit in which the controller110 changes c or an interval which is between a plurality of c'sacquired by the controller 110 may be predetermined.

Here, for example, a predetermined interval which is between theplurality of c's or a predetermined unit in which c is changed may be adip described above. Here, the predetermined interval between theplurality of c's may refer to the difference between c's which arecontinuously changed. For example, when c1, c2, and c3 included in theplurality of c's are continuous, the interval between the plurality ofc's may refer to a difference between c1 and c2.

Alternatively, as another example, a predetermined interval which isbetween a plurality of c's or a unit in which c is changed may be basedon the number of images the controller 110 acquires for one second.Specifically, the number of images the controller 110 acquires for onesecond may be a sampling rate, and the predetermined interval of theplurality of c's or a unit in which c is changed may be an inversenumber of the sampling rate.

Alternatively, as another example, the predetermined interval which isbetween the plurality of c's or the unit in which c is changed may be aminimum unit in which the controller 110 can change the phase. Here, theminimum unit in which the controller 110 can change the phase may be aunit in which coordinate information acquired based on the drivingsignal or the reconstruction signal is substantially changed.

Here, the controller 110 may acquire, in the form of a lookup table, aplurality of pieces of coordinate information acquired based on timeinformation corresponding to the minimum offset and reconstructionsignals obtained by changing c of the reconstruction signal to aplurality of values, and light information corresponding to theplurality of pieces of coordinate information. That is, when thecontroller 110 outputs a plurality of pieces of coordinate informationacquired based on time information corresponding to the minimum offsetand the reconstruction signals acquired by changing c of thereconstruction signal to a plurality of values, the controller 110 mayoutput coordinate information corresponding to the plurality of piecesof coordinate information acquired based on the time informationcorresponding to the minimum offset and the reconstruction signalsacquired by changing c of the reconstruction signal to the plurality ofvalues all at once.

Referring to FIG. 32 , the operation of the controller 110 correctingthe phase of the reconstruction signal on the basis of the first phasecorrection value and the second phase correction value (S7600) mayinclude the controller 110 setting the phases of the first-axis signaland the second-axis signal of the reconstruction signal as the firstphase correction value and the second phase correction value.

Specifically, referring to Equation 1 and 4 above, the controller 110may set t_(d) or φ_(x), which is the phase of the first-axis signal, asthe first phase correction value and may set t_(d)+c or φ_(y), which isthe phase of the second-axis signal, as the sum of the first phasecorrection value and the second phase correction value.

Here, the controller 110 correcting the phase of the reconstructionsignal may mean that the controller 110 sets the phase of thereconstruction signal to a specific phase.

3.3.5. SRSA

An example in which the controller 110 adjusts the phase of thereconstruction signal using an SRSA method will be described below.

Here, “SRSA” is an abbreviation of “Sequential Region Phase SearchAlgorithm” and may refer to a method of the controller 110 acquiring adetailed phase correction value of the reconstruction signal on thebasis of the tendency of the difference value between the pieces oflight information acquired for at least one piece of pixel informationto decrease as the phase of the reconstruction signal approaches a finalphase correction value.

Here, the final phase correction value may be the phase of the delayedreconstruction signal. Alternatively, the final phase correction valuemay be the phase of the reconstruction signal acquired by the controller110 through the detailed phase correction method.

Also, here, the tendency may mean that there is a slope at which thedifference value between the pieces of light information acquired for atleast one piece of pixel information decreases in proportion to a changein phase as the phase of the reconstruction signal approaches the finalphase correction value. Alternatively, the tendency may refer toconvexity in which there is a slope at which the difference valuebetween the pieces of light information acquired for at least one pieceof pixel information decreases in proportion to a change in phase as thephase of the reconstruction signal approaches the final phase correctionvalue. That is, accordingly, when the phase of the reconstruction signalapproaches the final phase correction value, the difference valuebetween the pieces of light information acquired for at least one pieceof pixel information exhibits convexity in a region in close proximityto the final phase correction value.

FIG. 34 includes graphs showing a difference value between pieces oflight information acquired for at least one piece of pixel informationexhibited when the phase of a reconstruction signal is changed accordingto an embodiment.

Here, in FIG. 34 , the x-axis represents the phase of a first-axissignal or a second-axis signal of the reconstruction signal, and they-axis represents a difference value among the light informationacquired for each of pixel information, and in particular, the varianceof pieces of light information. In this case, the negative sign of thephase of the first-axis signal or the second-axis signal of thereconstruction signal may mean that the last value in the phase range inwhich the first-axis signal or the second-axis signal is repeated isused as a reference value.

Specifically, referring to FIG. 34 , (a) of FIG. 34 is a graph showing adifference value among the light information acquired for each of pixelinformation acquired in the entire phase range of the first-axis signalor the second-axis signal of the reconstruction signal, and (b) of FIG.34 is a graph showing a difference value among the light informationacquired for each of pixel information acquired in a partial phase rageof the first-axis signal or the second-axis signal of the reconstructionsignal, which is in a first tendency range of (a) of FIG. 34 .

Here, the difference value between the pieces of light informationacquired for the pixel information may be, for example, the sum ofdifference values between the pieces of the light information acquiredfor the pixel information. However, the present invention is not limitedthereto, and the difference value between the pieces of lightinformation acquired for the pixel information may be the aforementioneddifference value.

Here, the entire phase range may mean that the phase range of thereconstruction signal is from 0 to 2π in the radian range. Here, theradian range may be changed to a time range. The radian range may bechanged to the time range by the frequency of the first-axis signal orthe second-axis signal of the reconstruction signal.

According to an embodiment, the difference value between the pieces oflight information acquired for the pixel information according to thephase of the first-axis signal or the second-axis signal of thereconstruction signal may exhibit a phase change-caused tendency.

For example, referring to FIG. 34 , in the range other than the firsttendency range of the entire phase range of the reconstruction signal,the difference value between the pieces of light information acquiredfor the pixel information may not exhibit a phase change-causedtendency.

However, in the first tendency range of the entire phase range of thereconstruction signal, a difference value among the light informationacquired for each of pixel information at a specific phase may exhibit aphase change-caused tendency.

According to an embodiment, the controller 110 may acquire the phase ofthe reconstruction signal belonging to the first tendency region usingan initial phase correction method.

That is, an initial phase correction value of the reconstruction signalacquired by the controller 110 using the initial phase correction methodmay be a phase in the first tendency range.

FIG. 35 is a graph showing a difference value between pieces of lightinformation acquired in at least one piece of pixel informationaccording to the phase of a reconstruction signal when the controller110 changes the phase of the reconstruction signal to a phase indicatinga specific FF according to an embodiment.

Here, in FIG. 35 , the x-axis represents the phase of a first-axissignal or a second-axis signal of the reconstruction signal, and they-axis represents a difference value among the light informationacquired for each of pixel information, and in particular, the varianceof pieces of light information.

Referring to FIG. 35 , when the controller 110 acquires the differencevalue between the pieces of light information acquired for the pixelinformation by changing the phase of the reconstruction signal to thephase indicating the specific FF, a difference value caused by the phaseof the reconstruction signal may exhibit no peaks and exhibit a certaintendency caused by the change of the phase.

Here, the difference value caused by the phase of the reconstructionsignal exhibiting a peak may indicate that the FF caused by the phase ofthe reconstruction signal vary.

In this case, when the difference value caused by the phase of thereconstruction signal exhibits a peak, the controller 110 may acquire avalue other than the final phase correction value as the detailed phasecorrection value of the reconstruction signal. Here, the controller 110acquiring the other phase correction value as the detailed phasecorrection value of the reconstruction signal may mean that thedifference value between the pieces of light information acquired forthe pixel information is acquired when the difference value is a localminimum value. Also, the controller 110 acquiring the detailed phasecorrection value of the reconstruction signal may mean that thedifference value between the pieces of light information acquired forthe pixel information is acquired when the difference value is a localminimum value.

According to an embodiment, referring to FIG. 35 , when the differencevalue between the pieces of light information acquired for the pixelinformation has the tendency, the controller 110 may correct the phaseof the reconstruction signal on the basis of the tendency.

A method of the controller 110 correcting the phase of thereconstruction signal on the basis of a certain tendency when thedifference value between the pieces of light information acquired forthe pixel information has the tendency will be described below.

FIG. 36 is a flowchart illustrating a method of the controller 110acquiring a final phase correction value of a reconstruction signalusing a tendency according to an embodiment.

Referring to FIG. 36 , the method of the controller 110 acquiring thefinal phase correction value of the reconstruction signal using thetendency may include an operation of the controller 110 acquiring thephase of a reconstruction signal with the largest FF in close proximityto an initial phase correction value (S8000), an operation of thecontroller 110 acquiring an intermediate phase correction value at whicha difference value among the light information acquired for at least onepiece of pixel information is minimized from the phase of thereconstruction signal with the largest FF on the basis of a tendency(S8200), and an operation of the controller 110 acquiring a final phasecorrection value at which the difference value between the pieces oflight information acquired for the at least one piece of pixelinformation from the intermediate phase correction value on the basis ofthe tendency (S8400).

Here, the method of the controller 110 acquiring the final phasecorrection value of the reconstruction signal using the tendency may beincluded in the operation of the controller 110 acquiring the detailedphase correction value (S4200).

Referring to FIG. 36 , the operation of the controller 110 acquiring thephase of the reconstruction signal with the largest FF in closeproximity to the first phase correction value (S8000) may include thecontroller 110 performing detailed phase correction on the basis of theinitial phase correction value, which is a phase in the first tendencyrange.

Here, the proximity to the initial phase correction value may mean thata dip-based range is set with respect to the initial phase correctionvalue. Specifically, the proximity to the initial phase correction valuemay mean that the controller 110 has a phase range equal to half of thedip with respect to the initial phase correction value.

Also, here, the acquisition of the phase of the reconstruction signalwith the largest FF may mean that the density of pixel information forwhich light information is acquired is high.

Referring to FIG. 36 , the operation of the controller 110 acquiring theintermediate phase correction value at which the difference value amongthe light information acquired for the at least piece of pixelinformation is minimized from the phase of the reconstruction signalwith the largest FF on the basis of the tendency (S8200) may include thecontroller 110 acquiring the intermediate phase correction value on thebasis of a tendency-based minimum search method.

Here, the tendency-based minimum search method may be a slope-basedsearch algorithm including the Nelder-Mead method, momentum method,AdaDrad method, Adam method, steepest gradient method, or gradientdescent method.

For example, the tendency-based minimum search method may mean that thecontroller 110 changes the phase of the reconstruction signal by as muchas the dip and uses a difference value between pieces of lightinformation acquired for at least one piece of pixel information usingcoordinate information acquired based on a reconstruction signalcorresponding to the phase changed by as much as the dip.

Alternatively, the tendency-based minimum search method may mean thatthe controller 110 changes the phase of the reconstruction signal by aninteger multiple of the dip and uses a difference value between piecesof light information acquired for at least one piece of pixelinformation using coordinate information acquired based on areconstruction signal corresponding to the phase changed by the integermultiple of the dip. Here, the integer multiple of the dip, which is aunit for the change, may be a different integer multiple each time thephase of the reconstruction signal is changed.

Alternatively, the tendency-based minimum search method may mean thatthe controller 110 changes the phase of the reconstruction signal in apredetermined phase correction unit other than the dip and uses adifference value between pieces of light information acquired for atleast one piece of pixel information using coordinate informationacquired based on a reconstruction signal corresponding to the phasechanged by the predetermined phase correction unit.

In this case, the controller 110 may acquire an intermediate phasecorrection value at which the difference value between the pieces oflight information acquired for the pixel information is minimized usingthe phase of the reconstruction signal changed based on the tendency.

FIG. 37 is a graph showing a difference between pieces of lightinformation acquired for at least one piece of pixel informationexhibited when the phase of a reconstruction signal is changed in apartial phase domain of the reconstruction signal according to anembodiment.

Here, in FIG. 37 , the x-axis represents the phase of a first-axissignal or a second-axis signal of the reconstruction signal, and they-axis represents a difference value among the light informationacquired for each of pixel information, and in particular, the varianceof pieces of light information.

In this case, referring to FIG. 37 , even in a second tendency range, achange in the difference value between the pieces of light informationacquired for the pixel information according to a change in the phase ofthe reconstruction signal may exhibit a tendency.

Also, referring to FIG. 37 , the range of an x-axis region of FIG. 37may be a dip.

Referring to FIGS. 36 and 37 , the operation of the controller 110acquiring the final phase correction value at which the difference valuebetween the pieces of light information acquired for the at least onepiece of pixel information from the intermediate phase correction valueon the basis of the tendency (S8400) may include the controller 110acquiring the final phase correction value in the second tendency range,which is a portion of the phase range of the acquired reconstructionsignal, on the basis of the tendency.

Here, the intermediate phase correction value acquired by the controller110 may be in the second tendency range.

According to an embodiment, even in the second tendency range, thecontroller 110 may acquire the final phase correction value on the basisof the tendency.

In this case, the controller 110 may acquire the final phase correctionvalue at which the difference value between the pieces of lightinformation acquired for the pixel information acquired based on thechanged phase of the reconstruction signal is minimized.

Here, the controller 110 may set a unit for changing the phase in thesecond tendency range to a predetermined unit smaller than the dip.

Accordingly, in order to search for the minimum based on the tendency,the controller 110 may change the phase in a predetermined unit smallerthan the dip and acquire the final phase correction value at which thedifference value between the pieces of light information acquired forthe at least one piece of pixel information is minimized.

Alternatively, the controller 110 may set a unit for changing the phasein the second tendency range to an integer multiple of the predeterminedunit less than the dip.

Accordingly, in order to search for the minimum based on the tendency,the controller 110 may change the phase in an integer multiple of thepredetermined unit smaller than the dip and acquire the final phasecorrection value at which the difference value between the pieces oflight information acquired for the at least one piece of pixelinformation is minimized.

FIG. 38 is a flowchart illustrating a method of the controller 110acquiring a final phase correction value of a reconstruction signalusing a slope-based minimum search technique according to an embodiment.

Here, the method of the controller 110 acquiring the final phasecorrection value of the reconstruction signal using the slope-basedminimum search technique may be included in the operation of thecontroller 110 acquiring the detailed phase correction value (S4200).

Referring to FIG. 38 , the method of the controller 110 acquiring thefinal phase correction value of the reconstruction signal using theslope-based minimum search technique may include an operation of thecontroller 110 searching for a first phase correction value using afirst slope-based search technique (S9000), an operation of thecontroller 110 comparing the difference value among the lightinformation acquired for the at least one piece of pixel information toa predetermined difference value or comparing a phase unit variationchanged in the first slope-based search technique to a predeterminedphase variation when correcting the reconstruction signal with the firstphase correction value (S9200), an operation of the controller 110searching for a second phase correction value using a second slope-basedsearch technique (S9400), and an operation of the controller 110comparing the difference value between the pieces of light informationacquired for the at least one piece of pixel information to apredetermined difference value or comparing a phase unit variationchanged in the second slope-based search technique to a predeterminedphase variation when correcting the reconstruction signal with thesecond phase correction value (S9600).

Referring to FIG. 38 , the operation of the controller 110 searching forthe first phase correction value using the first slope-based searchtechnique (S9000) may include the controller 110 using the firstslope-based search technique to acquire a phase correction value of thereconstruction signal.

Here, the first slope-based search technique may refer to theabove-described tendency-based search method or slope-based minimumsearch algorithm.

In this case, the first slope-based search technique may includechanging the phase of the reconstruction signal to a different valueeach time a search is made and searching for a phase value of thereconstruction signal at which the difference value between the piecesof light information acquired for the at least one piece of pixelinformation is minimized.

Also, the first phase correction value may be acquired as a result ofthe first slope-based search technique, but the controller 110 mayacquire the first phase correction value on the basis of the result ofthe first slope-based search technique.

Specifically, a phase correction value of the reconstruction signalacquired by the result of the first slope-based search technique may bea first intermediate phase correction value. In this case, the firstphase correction value may be a phase value indicating the maximum FFamong phases adjacent to the first intermediate phase correction value.

Referring to FIG. 38 , the operation of the controller 110 comparing thedifference value among the light information acquired for the at leastone piece of pixel information to the predetermined difference value orcomparing the phase unit variation changed in the first slope-basedsearch technique to the predetermined phase variation when correctingthe reconstruction signal with the first phase correction value (S9200)may include the controller 110 additionally correcting the first phasecorrection value on the basis of the predetermined difference value orthe predetermined phase variation.

Specifically, when the difference value between the pieces of lightinformation acquired for the at least one piece of pixel information isgreater than the predetermined difference value while the controller 110corrects the reconstruction signal on the basis of the first phasecorrection value acquired in the previous operation, the operation ofthe controller 110 searching for the first phase correction value usingthe first slope-based search technique (S9000) may be performed againbased on the first phase correction value acquired in the previousoperation. Here, a first phase correction value acquired in thisoperation may be different from the first phase correction valueacquired in the previous operation.

Likewise, when a variation of the phase changed to acquire the firstphase correction value in the first slope-based search technique isgreater than a predetermined phase variation while the controller 110corrects the reconstruction signal on the basis of the first phasecorrection value acquired in the previous operation, the operation ofthe controller 110 searching for the first phase correction value usingthe first slope-based search technique (S9000) may be performed again onthe basis of the first phase correction value acquired in the previousoperation.

Also, when the difference value between the pieces of light informationacquired for the at least one piece of pixel information is smaller thanthe predetermined difference value while the controller 110 corrects thereconstruction signal on the basis of the first phase correction valueacquired in the previous operation, the operation of the controller 110searching for the second phase correction value using the secondslope-based search technique (S9400) may be performed based on the firstphase correction value acquired in the previous operation.

Likewise, when a variation of the phase changed to acquire the firstphase correction value in the first slope-based search technique issmaller than the predetermined phase variation while the controller 110corrects the reconstruction signal on the basis of the first phasecorrection value acquired in the previous operation, the operation ofthe controller 110 searching for the second phase correction value usingthe second slope-based search technique (S9400) may be performed basedon the first phase correction value acquired in the previous operation.

Here, the predetermined phase variation or the predetermined differencevalue may be a value that is arbitrarily set by a user in considerationof the amount of computation of the controller 110.

Referring to FIG. 38 , the operation of the controller 110 searching forthe second phase correction value using the second slope-based searchtechnique (S9400) may include the controller 110 using the secondslope-based search technique to acquire a phase correction value of thereconstruction signal.

Here, the second slope-based search technique may use the same method asthe first slope-based search technique, but the first slope-based searchtechnique and the second slope-based search technique may search for aminimum on the basis of different phase variations.

As a specific example, the first slope-based search technique and thesecond slope-based search technique may search for the minimum whilechanging the phase of the reconstruction signal such that the phase isan integer multiple of a specific phase variation. However, the presentinvention is not limited thereto, and the first slope-based searchtechnique and the second slope-based search technique may search for theminimum on the basis of a constant multiple of a specific phasevariation, wherein the multiple may refer to a multiple of a numberincluding integers, rational numbers, and irrational numbers.

Referring to FIG. 38 , the operation of the controller 110 comparing thedifference value between the pieces of light information acquired forthe at least one piece of pixel information to the predetermineddifference value or comparing the phase unit variation changed in thesecond slope-based search technique to the predetermined phase variationwhen correcting the reconstruction signal with the second phasecorrection value (S9600) may include the controller 110 additionallycorrecting the second phase correction value on the basis of thepredetermined difference value or the predetermined phase variation.

Specifically, the operation of the controller 110 comparing thedifference value between the pieces of light information acquired forthe at least one piece of pixel information to the predetermineddifference value or comparing the phase unit variation changed in thesecond slope-based search technique to the predetermined phase variationwhen correcting the reconstruction signal with the second phasecorrection value (S9600) may be similar to the above operation of thecontroller 110 comparing the difference value among the lightinformation acquired for the at least one piece of pixel information tothe predetermined difference value or comparing the phase unit variationchanged in the first slope-based search technique to the predeterminedphase variation when correcting the reconstruction signal with the firstphase correction value (S9200).

That is, when the difference value between the pieces of lightinformation acquired for the at least one piece of pixel information isgreater than the predetermined difference value while the controller 110corrects the reconstruction signal on the basis of the second phasecorrection value acquired in the previous operation, the operation ofthe controller 110 searching for the second phase correction value usingthe second slope-based search technique (S9400) may be performed againbased on the second phase correction value acquired in the previousoperation. Here, a second phase correction value acquired in thisoperation may be different from the second phase correction valueacquired in the previous operation.

Likewise, when a variation of the phase changed to acquire the secondphase correction value in the second slope-based search technique isgreater than a predetermined phase variation while the controller 110corrects the reconstruction signal on the basis of the second phasecorrection value acquired in the previous operation, the operation ofthe controller 110 searching for the second phase correction value usingthe second slope-based search technique (S9400) may be performed againon the basis of the second phase correction value acquired in theprevious operation.

Also, when the difference value between the pieces of light informationacquired for the at least one piece of pixel information is smaller thanthe predetermined difference value while the controller 110 corrects thereconstruction signal on the basis of the second phase correction valueacquired in the previous operation, the controller 110 may set thesecond phase correction value acquired in the previous operation as thefinal phase correction value of the reconstruction signal.

Likewise, when a variation of the phase changed to acquire the secondphase correction value in the second slope-based search technique issmaller than the predetermined phase variation while the controller 110corrects the reconstruction signal on the basis of the second phasecorrection value acquired in the previous operation, the controller 110may set the second phase correction value acquired in the previousoperation as the final phase correction value of the reconstructionsignal.

Likewise, the predetermined phase variation or the predetermineddifference value may be a value that is arbitrarily set by a user inconsideration of the amount of computation of the controller 110. Thepredetermined difference value or the predetermined phase variation inthe operation of the controller 110 comparing the difference valuebetween the pieces of light information acquired for the at least onepiece of pixel information to the predetermined difference value orcomparing the phase unit variation changed in the second slope-basedsearch technique to the predetermined phase variation when correctingthe reconstruction signal with the second phase correction value (S9600)may be different from the predetermined difference value or thepredetermined phase variation in the above operation of the controller110 comparing the difference value among the light information acquiredfor the at least one piece of pixel information to the predetermineddifference value or comparing the phase unit variation changed in thefirst slope-based search technique to the predetermined phase variationwhen correcting the reconstruction signal with the first phasecorrection value (S9200).

According to an embodiment, the above method of the controller 110searching for a phase correction value for correcting the phase of thereconstruction signal may be interchangeably used.

Also, according to an embodiment, the controller 110 may simultaneouslycorrect the phases of the first-axis signal and the second-axis signalof the reconstruction signal. Here, the controller 110 simultaneouslycorrecting the phases may mean that the controller 110 corrects thephases of the first-axis signal and the second-axis signal of thereconstruction signal using the methods of the above-describedembodiments.

Also, according to an embodiment, the controller 110 may sequentiallycorrect the phases of the first-axis signal and the second-axis signalof the reconstruction signal. In other words, the controller 110 maycorrect the phase of the first-axis signal of the reconstruction signalfirst and then correct the phase of the second-axis signal or maycorrect the phase of the second-axis signal of the reconstruction signalfirst and then correct the phase of the first-axis signal. Here, thecontroller 110 simultaneously correcting the phases may mean that thecontroller 110 corrects the phases of the first-axis signal and thesecond-axis signal of the reconstruction signal using the methods of theabove-described embodiments.

According to an embodiment of the present invention, it is possible toacquire a clear image in real time by correcting an image using atendency.

According to an embodiment of the present invention, it is also possibleto acquire a high-resolution image by adjusting the frequency of animage reconstruction signal.

According to an embodiment of the present invention, it is also possibleto correct an image at high speed by transforming the domain of an imagereconstruction signal to correct the phase of the reconstruction signal.

Although the present invention has been described with reference tospecific embodiments and drawings, it will be appreciated that variousmodifications and changes can be made from the disclosure by thoseskilled in the art. For example, appropriate results may be achievedalthough the described techniques are performed in an order differentfrom that described above and/or although the described components suchas a system, a structure, a device, or a circuit are combined in amanner different from that described above and/or replaced orsupplemented by other components or their equivalents.

Therefore, other implementations, embodiments, and equivalents arewithin the scope of the following claims.

What is claimed is:
 1. An image generating device comprising: a lightsource; a laser scanner; a light-receiving unit; and a control module,wherein the control module is configured to: generate a first drivingsignal corresponding to a first axis and a second driving signalcorresponding to a second axis that is different from the first axis;control the laser scanner to irradiate a first light from the lightsource to an object in a pre-determined pattern based on the firstdriving signal and the second driving signal; control thelight-receiving unit to obtain a second light from the object based onthe first light; generate coordinate information in a phase domain basedon time information of the first driving signal and the second drivingsignal; and generate a first image by mapping information on the secondlight to the coordinate information.
 2. The image generating device ofclaim 1, wherein the control module is configured to: determine a firstphase delay value corresponding to the first driving signal and a secondphase delay value corresponding to the second driving signal on thebasis of identification of at least two regions corresponding to eachother in the first image; and generate a second image based on the firstphase delay value and the second phase delay value.
 3. The imagegenerating device of claim 2, wherein the at least two regionscorresponding to each other are the at least two regions that aresymmetrical to each other.
 4. The image generating device of claim 1,wherein the information on the detected light comprises a lightintensity value.
 5. The image generating device of claim 1, wherein thecontrol module is configured to generate the first image by mapping thecoordinate information corresponding to a plurality of time points withlight intensity values each corresponding to one of the plurality oftime points.
 6. The image generating device of claim 1, wherein thecontrol module is configured to apply the first driving signal accordingto A_(x) sin(2πf_(x)t+φ_(x)) and apply the second driving signalaccording to A_(y) sin(2πf_(y)t+φ_(y)), and the first image is an imagegenerated by causing a light intensity value (It) to correspond tocoordinates expressed by (A_(x)(2πf_(x)t+φ_(x))(mod 2π),(A_(y)(2πf_(y)t+φ_(y))(mod 2π) in the phase domain, wherein t denotes atime value in a range of Ts to (Ts+T) (Ts denotes an arbitrary timevalue and T denotes a repeat cycle), f_(x) denotes a first frequencycomponent of the first driving signal, φ_(x) denotes a first phasecomponent of the first driving signal, f_(y) denotes a second frequencycomponent of the second driving signal, φ_(y) denotes a second phasecomponent of the second driving signal, and the light intensity value(It) corresponds to the time value (t).